Control of cooling during spray forming of bearing steel billets

Materials Science and Engineering A 383(2004)

158–165

Control of cooling during spray forming of bearing steel billets

Chengsong Cui ?,Udo Fritsching,Alwin Schulz,Klaus Bauckhage,Peter Mayr

University of Bremen,SFB570,Badgasteiner Str.3,28359Bremen,Germany

Received 27January 2004

Abstract

In an effort to minimize the distortion of bearing steel rings during the production process,100Cr6steel billets are spray formed with a unique cooling control system to control the cooling and solidi?cation behavior of the deposits.Effects of heating around the de-posits,gas cooling at the substrate bottom and the gas ?ow over the deposits are investigated both by numerical simulation and exper-iment.Porosity pro?les and microstructures of spray formed bearing steel are examined and evaluated.The investigation results show that the thermal boundary conditions of the deposits play important roles on the cooling and solidi?cation behavior of the deposits,espe-cially at the deposit periphery.Porosity in the 100Cr6bearing steel deposit can be reduced signi?cantly with the special cooling control system.

?2004Elsevier B.V .All rights reserved.

Keywords:Spray forming;Process development;Cooling strategies;Modeling

1.Introduction

Requirements for the components for rolling contact bear-ing applications are not only high hardness and high fatigue resistance but also high dimensional stability during produc-tion and usage of ?nished parts.Very time and cost con-suming ?nal machining in the heat-treated state is required when distortion generated during the ?nal heat treatment re-quires large material allowance.Inhomogeneity of chemical composition and non-uniformity in microstructures are re-garded as the reasons for dimensional changes during heat treatment [1,2].

Spray forming,a novel metallurgical process with the characteristics of rapid solidi?cation,has been developed for the manufacture of near-net shape products.Intensive inves-tigation and evaluation of this process and relevant materials have been reported and documented [3–7].Chemical homo-geneity and ?ne uniform microstructures of the deposit are unique features of spray formed materials.Therefore,spray forming is a promising approach for the production of dis-tortion insensitive bearing steel.A commercial bearing steel 100Cr6has been spray formed previously,and chemical ho-?

Corresponding author.Tel.:+49-421-2184031;fax:+49-421-2185378.

E-mail address:cscui@iwt.uni-bremen.de (C.Cui).

mogeneity was shown [8].Detailed study on the deposits made under various spray conditions (e.g.hot spray and cold spray)showed that thermal spray condition played an im-portant role in the quality (e.g.,microstructure and porosity)of the deposit.It indicated that the thermal boundary con-dition strongly in?uenced the overall metallurgical homo-geneity of the deposit.For the cold billet,there was a large amount of porosity especially at the periphery due to rapid cooling of depositing material and no additional melt ?lling the shrinkage.For the hot billet there was a larger difference of grain structure across the billet and even hot cracks might take place in the ?nal solidi?cation zone.How to improve the deposit quality (i.e.more uniform grain structure and less porosity in surface area)so as to minimize distortion of bearing steel components during subsequent production process is a very important task for spray forming research.In the present study,100Cr6steel billets were spray formed with a unique cooling control system,which was used to control the cooling and solidi?cation of the billets during spray forming.With the help of the cooling control system,the radial thermal pro?le distribution of the deposit was expected to be more uniform,resulting in more homo-geneous structure.Effects of heating from a furnace around the deposit and gas cooling at the substrate bottom as well as the gas ?ow over the deposit were investigated both by numerical simulation and experiment.Porosity pro?les and

0921-5093/$–see front matter ?2004Elsevier B.V .All rights reserved.doi:10.1016/j.msea.2004.02.058

C.Cui et al./Materials Science and Engineering A 383(2004)158–165159

microstructure characteristics of the spray formed bearing steel were examined and evaluated.

2.Modeling and numerical simulation 2.1.Mathematical model

In the spray forming process,the heat transfer of a de-posit can be classi?ed into several modes as shown in Fig.1:(1)conductive heat transfer inside the deposit;(2)heat ?ux to the substrate from the deposit bottom by convective heat transfer ˙q s ;(3)heat released from the deposit surface to sur-rounding gas ?ow by gas convection ˙q g and (4)heat loss to the environment by radiation ˙q ε.Apparently the cooling and solidi?cation of deposit are closely dependent on the heat transfer boundary conditions,which may be adjusted and controlled in the spray forming process.To produce a homogeneous deposit,the cooling and solidi?cation condi-tions either in the center or at the rim of the deposit should be similar.Therefore,the heat transfer from the free surface of the deposit to the environment should be suppressed while the heat ?ow directed to the substrate should be enhanced.For fundamental understanding of the effects of thermal boundary conditions on the spray forming process,mathe-matical modeling and numerical simulation of the heat trans-fer of deposit have been established.The governing equation for the heat transfer inside the deposit can be given by:?

?t

(H)=?(λ?T)(1)

where H is the total enthalpy,T the temperature and λthe thermal conductivity of the deposit.

The boundary conditions to specify the above governing equation can be expressed as follows:

(1)At the deposit–substrate interface the heat ?ux between

the deposit and substrate can be described as:

˙q s =h s (T ?T s )

(2)

Fig.1.Heat transfer modes of a deposit and the cooling control system used in spray forming.

where h s is the heat transfer coef?cient between the deposit and the substrate;T s the top surface temperature of the substrate.

(2)At the free surface of the deposit the heat ?ux involves

convective heat transfer and radiation.The heat ?ux due to gas convection can be written as:

˙q g =h g (T ?T g )

(3)

where T g is the gas temperature and h g the convective heat transfer coef?cient.The heat ?ux from the surface to the environment by radiation is determined by:

˙q ε=σ×ε(T 4?T 4

w )

(4)

where σis the Stefan–Boltzmann constant (5.6697×10?8W m ?2K ?4)and εthe emissivity;T w the temper-ature of the spraying chamber wall.2.2.Numerical method

The heat transfer modeling described above is coupled with the time-dependent geometry of the growing billet.To simplify the simulation work,growth of billet is assumed to be in the way of adding layers of uniform thickness one af-ter another to the numerical grid system.Orthogonal grids are established in the cylinder deposit for numerical simula-tion.For discretization of the governing equation,an explicit ?nite-difference method is used.2.3.Parameters for computation

The thermophysical properties of 100Cr6steel for de-posit and low carbon steel for substrate were found in ref.[9,10].The atomizing gas temperature and the temperature of the spraying chamber wall are assumed to be constant 250?C during spray forming and subsequent cooling pro-cess.The initial temperature of low carbon steel substrate is set as 30?C.In the present modeling an average en-thalpy method is used,assuming that the impinging layer has a uniform enthalpy all over the deposit surface (f l =0.5).

160 C.Cui et al./Materials Science and Engineering A383(2004)158–165 Table1

Typical thermal boundary conditions for numerical simulation

Boundary condition Temperature of chamber wall,T wall(?C)Heat transfer coef?cient(W m?2K?1)

During deposition Post-deposition At deposit and substrate side

surface,h g At the substrate bottom surface,h bottom

During deposition Post-deposition During deposition Post-deposition

(a)Standard2502501701017010

(b)Side heating100010001701017010

(c)Bottom cooling25025017010500500

(d)Side isolating250250101017010

(e)((b)+(c)+(d))100010001010500500

The convective heat transfer coef?cient h g is set as 170W m?2K?1for the standard spray forming condition [11].At the end of spraying,the heat transfer coef?cient diminishes sharply since no additional atomizing gas sprays towards the billet,and a value of10W m?2K?1is assumed. The heat transfer coef?cient between the billet and the sub-strate is estimated to be1000W m?2K?1.The radiative heat?ux is greatly in?uenced by the emissivityεof the billet,for which the mean value of0.5is chosen for the computation[11].

The parameters described above are typical for the stan-dard spray forming condition of the spray forming facility SK1at the University of Bremen.In order to reveal the ef-fects of heat transfer boundary conditions on the thermal pro?les of the spray formed billets,numerical simulation has been carried out for the case of side heating,bottom cooling and side isolating(as listed in Table1).In the case of side heating,a furnace is proposed to be installed surrounding the deposit,and the inside wall temperature of the furnace is set as1000?C.For bottom cooling,it is assumed a gas jet sprays onto the bottom surface of substrate to cool it in-tensively.As to side isolating,the heat transfer coef?cients for the deposit and the substrate side surface are reduced to10W m?2K?1assuming that the deposit side surface is protected from the atomizing gas?ow under a shelter(e.g., the furnace around the deposit).In the last case,a combined effect of side heating,bottom cooling and side isolating is considered for calculation.

3.Experimental methods

To investigate the boundary conditions,a unique cooling control system was established in the spray forming facil-ity as illustrated in Fig.1.A furnace is placed around the substrate and the deposit to reduce or suppress the heat?ow released from the side surface of deposit.A gas stream is conducted through the motor shaft from below to intensively cool the substrate.

Typical bearing steel100Cr6(SAE52100),consisting of (wt.%):0.93–1.05C,0.15–0.35Si,0.25–0.45Mn,1.35–1.60 Cr,<0.025P,<0.015S,was used as the feedstock material.The melt stream at a superheat of180?C was atomized by

a scanning free fall atomizer using nitrogen at a pressure of

0.40–0.45MPa.The diameter of the pouring nozzle at the bottom of the tundish was4mm.Billets were spray-formed on a tilted rotating steel disc with a tilting angle of30?and a withdrawing speed of0.65mm s?1.

Heating from the furnace with a maximum inside wall temperature of700?C,gas cooling at the substrate bottom with a maximum gas?ow rate of100g s?1and modi?ed heat transfer coef?cient at the deposit side surface by adjust-ing the atomizing gas pressure are set as the three factors of a two-level orthogonal experiment design table,as listed in Table2.The heating factor is separated into two parts:heat-ing during spray deposition and post-heating afterwards,so two matrixes of orthogonal experiment design can be estab-lished.Exp.SK1-627is not within these two matrixes,but it is used for additional comparison with Exp.SK1-615and Exp.SK1-646to get more information about the in?uence of boundary conditions.

Optical microscopy was conducted on the as-deposited samples taken along the radius and height of the spray formed deposits,as shown in Fig.2.Nital was used to reveal the morphology of pearlite phase.For density measurement Archimede’s method was used as described in DIN EN6018. Optical emission spectrometry(ARL,Typ34000C7B)was used to analyze the distribution of chemical composition in the spray formed

billets.

Fig.2.Samples taken from a deposit for porosity investigation.

C.Cui et al./Materials Science and Engineering A 383(2004)158–165

161

Table 2

Orthogonal experiment design for spray forming of 100Cr6steel billets Exp.no.Gas ?ow (P g ,MPa)Heating Post-heating Gas cooling Orthogonal design matrix SK1-5730.4N N N (A1)

SK1-6150.4Y N N (B1)

SK1-6270.4Y N Y SK1-6290.4Y Y Y (A2)(B2)SK1-6470.45N N Y (A3)SK1-6460.45Y N Y (B3)SK1-645

0.45

Y

Y

N

(A4)

(B4)

4.Results and discussion 4.1.Simulation results

The numerical simulation for the thermal pro?les of the spray formed bearing steel billets was ?rst done for the stan-dard spray forming condition de?ned in Table 1.Fig.3shows the calculated temperature and liquid fraction distributions of a billet at different spraying times.At the beginning of de-position,the material is almost completely solidi?ed due to the chilling effect of the cold substrate.The overall tempera-ture and local liquid fraction in the billet increase as the billet grows,i.e.,the total liquid mass or mushy zone at the top of the billet increases.At the end of spraying (t =200s),the highest residual liquid fraction reaches approximately 0.3.After the spraying period,the billet cools down slowly and the residual liquid solidi?es in the top center area.Because of the low thermal conductivity of the 100Cr6bearing steel,the temperature differences from the billet top to bottom as well as along the radius are relatively high.Even when the convective heat transfer coef?cient drops sharply at the end of spraying,an uneven radial temperature distribution still exists.

Local solidi?cation time was used to study the cooling and solidi?cation behavior of the deposits.Fig.4shows the isochronous solidi?cation lines of the deposit from 10up to 350s.When the local solidi?cation time in

the Fig.3.Temperature and liquid fraction distributions in the deposit and substrate during spray forming.

periphery area increases,the shrinkage porosity would be reduced.

Fig.4b shows the solidi?cation pro?les of the deposit under the side heating condition,which shows that all isochronous lines move rightward,indicating that it takes longer time for the deposit to solidify.In the case of bot-tom cooling (see Fig.4c ),no signi?cant change of the plot can be found compared to the standard case due to the low conductivity of the steel substrate.As the deposit is isolated from the atomizing gas jet,the heat transfer coef?cient of convective heat ?ow decreases remarkably,resulting in less heat transfer from the side surface of deposit to the gaseous environment.Accordingly the isochron lines in Fig.4d move to the right as well.When the effects of side heating,bottom cooling and side isolating are combined,signi?cant changes of the local solidi?cation times of the deposit are noticed in Fig.4e ,which shows that the fast cooling and so-lidi?cation process of the deposit at the periphery commonly for the standard processing condition are slowed down.The effects of the cooling control on the thermal pro?les of deposit are also re?ected by the heat ?ows at the surfaces of deposit,as shown in Fig.5.For the standard spray con-dition (Fig.5a ),the heat ?ow by convection at the deposit bottom surface is very large because of the chilling effect of the cold substrate at the beginning of deposition.As the deposition process continues,the substrate temperature in-creases fast,causing the heat ?ow to decrease quickly.The

162 C.Cui et al./Materials Science and Engineering A 383(2004)

158–165

Fig.4.Local solidi?cation times of 100Cr6deposits under various boundary conditions of:(a)standard;(b)side heating;(c)bottom cooling;(d)side isolating;and (e)(b)+(c)+(d).

heat ?ows from the side surface of deposit by gas convection and radiation increase nearly linearly as the deposit grows.The heat ?ow released from the top surface of deposit main-tains at a relatively stable value during the spraying period,because the top surface temperature normally keeps constant as additional spray of droplets is continuously coming.At the end of spraying at 200s,heat ?ows by gas convection at the top and side surfaces of deposit drop dramatically since atomizing gas is switched off.The heat ?ows by side radia-tion and top radiation,as well as the heat ?ow at the deposit and substrate interface also decrease gradually since the tem-perature of deposit decreases during subsequent cooling pe-riod.For the cooling control condition (Fig.5b ),i.e.,side heating by furnace,bottom cooling by gas and reduced gas ?ow at the side surface of deposit,the heat ?ow by gas con-vection from the side surface of deposit diminishes greatly and the heat ?ow by radiation is reduced signi?cantly as well.The heat ?ow from the deposit bottom to the substrate is increased owing to enhanced gas cooling of substrate,but the effect is not very signi?cant.Nearly no change is found in the heat ?ow from the top surface of deposit because no heat transfer boundary condition has been modi?ed

there.

Fig.5.Heat ?ows at the surface of deposit in various modes and directions.

The above computation and analysis show that it is im-possible to obtain an absolutely uniform thermal pro?le dis-tribution along the radius because of the existing heat ?ows at the free surfaces of deposit and low heat conductivity of steel.Nevertheless,control of the cooling and solidi?cation process of deposit,especially at the periphery,could be re-alized to some extent by adjusting the boundary conditions of heat transfer.4.2.Experimental results

Based on the simulation results,process parameters were selected for the production of billets under differ-ent boundary conditions as described in the last section.Deposit ‘SK1-573’was produced under the standard pro-cessing condition.Deposit ‘SK1-615’was made under the hottest condition and deposit ‘SK1-647’under the cold-est condition.These deposits were chosen for detailed investigation and for comparison.All the deposits were cross-sectioned from top to bottom and samples were taken and prepared for microstructure examination and density measurement.

C.Cui et al./Materials Science and Engineering A 383(2004)158–165

163

Fig.6.Relative density distributions of 100Cr6deposits under various processing conditions.

Fig.6shows the radial density distributions in the spray formed billets at the half height as well as the density dis-tribution along height direction.A low porosity level,better than 99%of the theoretical density,is obtained in the cen-ter of the billet.The periphery,however,has an increasing amount of large and irregular formed pores.At the outmost area of the deposits,a relative density of even lower than 90%is found.From the comparison of the seven deposits made under different boundary conditions,the density of the hot processed deposit ‘SK1-615’is the highest while the density of the cold processed deposit ‘SK1-647’is the low-est.The standard deposit ‘SK1-573’has a mean value of the densities.

The density distributions of the deposits are evidently as-sociated with its cooling and solidi?cation conditions during spray forming process.It is shown from the above compu-tation that the radial temperature distribution in the billet is uneven,i.e.,hot in the center and cold at the periphery.The cold rim has a chilling effect on the new adding layer,result-ing in a large amount of porosity in that region.The calcu-lated results quite agree with the experimental investigation.When the boundary conditions for heat transfer change,e.g.a furnace is heating around the deposit,the radiation heat ?ow from the deposit side surface to the environment is reduced.As a result,the cooling and solidi?cation

rates Fig.7.Microstructures of the deposit under standard processing condition (SK1573).

at the side rim of deposit slow down,decreasing the amount of cold shrinkage porosity.As the heat transfer coef?cient increases due to more intensive convective heat transfer by applying high atomizing gas pressure (4.5bar),the deposit cools faster,leading to more cold interstice porosity.Addi-tional cooling at the substrate bottom by gas jet seems to have no signi?cant in?uence on the cooling and solidi?ca-tion behavior of the deposit,which is also consistent with the simulation results.In comparison with the other two boundary conditions,gas ?ow behavior at the surface of the deposit is the most dominant factor in?uencing the cooling and solidi?cation process of the deposit.This result has also been approved by calculation of the total amount of heat ?ows of the deposit by different heat transfer modes.

The microstructures of the spray formed 100Cr6steel under the standard boundary condition are shown in Fig.7.In the center of the billet the pearlitic structure is relatively coarse,whereas at the periphery it re?nes greatly.The reason for the larger grain size in the center area is that the local cooling and solidi?cation rates of the deposit in this area is slower than those in the periphery area.

The pearlitic structures of the cold deposit and the hot de-posit seem to be not very different from those of the standard deposit,both in the center and at the periphery.However,some difference in the oxide layer and decarburization zone

164 C.Cui et al./Materials Science and Engineering A 383(2004)

158–165

Fig.8.Microstructures at the periphery of deposit under different processing

conditions.

Fig.9.Temperature and liquid fraction distributions in CuSn6alloy deposits under various boundary conditions of:(a)standard;(b)side heating;(c)bottom cooling;(d)side isolating;and (e)(b)+(c)+(d).

at the deposit surface exists,as shown in https://www.docsj.com/doc/5711030845.html,pared with the standard deposit ‘SK1-573’,the oxide layer and decarburization zone in the hot deposit ‘SK1-615’are much larger and thicker,which means that the hot deposit experi-enced a relatively hot state during the cooling and solidi?-cation stages than the standard deposit and the cold deposit.4.3.Further discussion

Although the metallurgical quality of the spray formed 100Cr6billets can be improved with the thermal con-trol system,absolute material homogeneity cannot be achieved for this type of deposit,because of its relative high volume-to-surface ratio.This is due to non-uniform cooling and solidi?cation behavior from the center to the periphery of the billets.Low thermal conductivity (30W m ?1K ?1)and high latent heat of fusion (287,000J kg ?1)of 100Cr6steel are the main barriers for uniform distributions of ther-mal pro?les.In comparison,if a material with high thermal conductivity and low latent heat of fusion (e.g.,CuSn6al-loy)is spray formed with the thermal control system,better distributions of thermal pro?les are expected within the bil-

let.Numerical simulation results of temperature and liquid fraction distributions in the CuSn6alloy deposits of same size under various boundary conditions (Table 1)are shown in Fig.9.The thermophysical properties of CuSn6alloy are found in the ref.[9],for which the value of thermal conductivity is 153W m ?1K ?1and the value of latent heat of fusion is 199,971J kg ?1.For such kind of material,the heat in the center of the billet is much easier to be trans-ferred to the periphery in comparison with 100Cr6steel.Moreover,the thermal control system used for the CuSn6billets is more effective on the control of cooling and solid-i?cation behavior compared with the 100Cr6billets.In the case of boundary condition (e),almost completely uniform distributions of thermal pro?les in the billet are attained.

5.Conclusion

100Cr6steel billets were spray formed with a unique cooling control system.The heat released from the deposit periphery by radiation can be reduced by the heating device installed around the deposit,but the effect of gas cooling at

C.Cui et al./Materials Science and Engineering A383(2004)158–165165

the substrate bottom is very much limited.Atomizing gas ?ow behavior over the surface of deposit plays a very im-portant role on the cooling and solidi?cation behavior of the deposits,especially in the outmost surface area.Porosity in the deposit,which is very sensitive to the thermal boundary conditions,can be reduced signi?cantly with the assistance from the special cooling control system.The pearlite struc-ture changes from the deposit center to the periphery due to different local cooling and solidi?cation rates.Thermophys-ical properties are very important factors in?uencing the material homogeneity.For a material like CuSn6alloy with high thermal conductivity and low latent heat of fusion, the thermal control system is much more effective on the control of cooling and solidi?cation behavior of deposits. Acknowledgements

This project is funded by the DFG(Deutsche Forschungs-gemeinschaft)program“Distortion Engineering”(SFB570/ A2)at the University of Bremen.

References

[1]W.T.Cook,Heat Treat.Met.2(1999)27.

[2]F.Hoffmann,J.Dong,T.Lübben,P.Mayr,Zeitschrift für Metal-

lkunde92(2001)242.

[3]A.G.Leatham,Mater.World4(1996)317.

[4]G.Leatham,https://www.docsj.com/doc/5711030845.html,wley,Int.J.Powder Metall.29(1993)321.

[5]https://www.docsj.com/doc/5711030845.html,wley,G.Leatham,Mater.Sci.Forum299-300(1999)

407.

[6]https://www.docsj.com/doc/5711030845.html,wley,Melt atomization&spray deposition—Quo Vadis,in:K.

Bauckhage,V.Uhlenwinkel,U.Fritsching(Eds.),Spray Deposition and Melt Atomization(SDMA2000),vol.1,Proceedings of the International Conference on Spray Deposition and Melt Atomization, University of Bremen,Bremen,Germany,2000,pp.3–15.

[7]https://www.docsj.com/doc/5711030845.html,vernia,Y.Wu,Spray Atomization and Deposition,John Wiley

and Sons Ltd.,Chichester,UK,1996.

[8]C.S.Cui,O.Meyer,H.Z?ller,U.Fritsching,A.Schulz,K.Bauck-

hage,P.Mayr,Production of homogeneous bearing steel billet by spray forming,in:V.Arnhold, C.Chu,W.F.Jandeska,Jr.,H.I.

Sanderow(Eds.),Advances in Powder Metallurgy&Particulate Materials-2002,Proceedings of the2002World Congress on Powder Metallurgy&Particulate Materials,Part4,Metal Powder Industries Federation,Princeton,USA,2002,pp.201–217.

[9]O.Meyer,U.Fritsching,K.Bauckhage,Int.J.Thermal Sci.42

(2003)153.

[10]T.P.Pederson,J.H.Hattel,N.H.Pryds,A.S.Pederson,M.Buch-

holz,V.Uhlenwinkel,A new integrated numerical model for spray atomization and deposition:comparison between numerical results and experiments,in:K.Bauckhage,V.Uhlenwinkel,U.Fritsching (Eds.),Spray Deposition and Melt Atomization,vol.2,Proceedings of the International Conference on Spray Deposition and Melt At-omization(SDMA2000),University of Bremen,Bremen,Germany, 2000,pp.813–824.

[11]V.Uhlenwinkel,M.Buchholz,R.Tinscher, A.Schulz,J.Fis-

cher,R.Schr?der,Investigation of spray formed billets from bear-ing steel AISI52100,in:A.Leatham(Eds.),Proceedings of the Fourth International Conference on Spray Forming,Baltimore,USA, 1999.

of与for的用法以及区别

of与for的用法以及区别 for 表原因、目的 of 表从属关系 介词of的用法 （1）所有关系 this is a picture of a classroom （2）部分关系 a piece of paper a cup of tea a glass of water a bottle of milk what kind of football，American of soccer？ （3）描写关系 a man of thirty 三十岁的人 a man of shanghai 上海人 （4）承受动作 the exploitation of man by man．人对人的剥削。 （5）同位关系 It was a cold spring morning in the city of London in England． （6）关于，对于 What do you think of Chinese food？ 你觉得中国食品怎么样？ 介词 for 的用法小结 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。What will we have for supper? 我们晚餐吃什么?

2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。

to与for的用法和区别

to与for的用法和区别 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb.表示对某人有直接影响比如，食物对某人好或者不好就用to; for表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语？ 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．对于 1．She has a liking for painting. 她爱好绘画。 2．She had a natural gift for teaching. 她对教学有天赋/ 3．表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法？ 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于（常有较活译法） 1 Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，对于（某人），对…来说（多和形容词连用）用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。 6．for和fit, good, bad, useful, suitable 等形容词连用，表示适宜，适合。 Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 Exercises are good for health. 锻炼有益于健康。 Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 You are not suited for the kind of work you are doing. 7. for表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 1．It would be best for you to write to him. 2．The simple thing is for him to resign at once. 3．There was nowhere else for me to go. 4．He opened a door and stood aside for her to pass.

常用介词用法(for to with of)

For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。 尽管for 的用法较多，但记住常用的几个就可以了。 to的用法: 一：表示相对，针对 be strange (common, new, familiar, peculiar) to This injection will make you immune to infection. 二：表示对比，比较 1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior 2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous A is similar to B in many ways.

(完整版)介词for用法归纳

介词for用法归纳 用法1：(表目的)为了。如： They went out for a walk. 他们出去散步了。 What did you do that for? 你干吗这样做？ That’s what we’re here for. 这正是我们来的目的。 What’s she gone for this time? 她这次去干什么去了？ He was waiting for the bus. 他在等公共汽车。 【用法说明】在通常情况下，英语不用for doing sth 来表示目的。如： 他去那儿看他叔叔。 误：He went there for seeing his uncle. 正：He went there to see his uncle. 但是，若一个动名词已名词化，则可与for 连用表目的。如： He went there for swimming. 他去那儿游泳。(swimming 已名词化) 注意：若不是表目的，而是表原因、用途等，则其后可接动名词。(见下面的有关用法) 用法2：(表利益)为，为了。如： What can I do for you? 你想要我什么？ We study hard for our motherland. 我们为祖国努力学习。 Would you please carry this for me? 请你替我提这个东西好吗？ Do more exercise for the good of your health. 为了健康你要多运动。 【用法说明】(1) 有些后接双宾语的动词(如buy, choose, cook, fetch, find, get, order, prepare, sing, spare 等)，当双宾语易位时，通常用for 来引出间接宾语，表示间接宾语为受益者。如： She made her daughter a dress. / She made a dress for her daughter. 她为她女儿做了件连衣裙。 He cooked us some potatoes. / He cooked some potatoes for us. 他为我们煮了些土豆。 注意，类似下面这样的句子必须用for： He bought a new chair for the office. 他为办公室买了张新办公椅。 (2) 注意不要按汉语字面意思，在一些及物动词后误加介词for： 他们决定在电视上为他们的新产品打广告。 误：They decided to advertise for their new product on TV. 正：They decided to advertise their new product on TV. 注：advertise 可用作及物或不及物动词，但含义不同：advertise sth＝为卖出某物而打广告；advertise for sth＝为寻找某物而打广告。如：advertise for a job=登广告求职。由于受汉语“为”的影响，而此处误加了介词for。类似地，汉语中的“为人民服务”，说成英语是serve the people，而不是serve for the people，“为某人的死报仇”，说成英语是avenge sb’s death，而不是avenge for sb’s death，等等。用法3：(表用途)用于，用来。如： Knives are used for cutting things. 小刀是用来切东西的。 This knife is for cutting bread. 这把小刀是用于切面包的。 It’s a machine for slicing bread. 这是切面包的机器。 The doctor gave her some medicine for her cold. 医生给了她一些感冒药。 用法4：为得到，为拿到，为取得。如： He went home for his book. 他回家拿书。 He went to his friend for advice. 他去向朋友请教。 She often asked her parents for money. 她经常向父母要钱。

of和for的用法

of 1....的,属于 One of the legs of the table is broken. 桌子的一条腿坏了。 Mr.Brown is a friend of mine. 布朗先生是我的朋友。 2.用...做成的;由...制成 The house is of stone. 这房子是石建的。 3.含有...的;装有...的 4....之中的;...的成员 Of all the students in this class,Tom is the best. 在这个班级中,汤姆是最优秀的。 5.(表示同位) He came to New York at the age of ten. 他在十岁时来到纽约。 6.(表示宾格关系) He gave a lecture on the use of solar energy. 他就太阳能的利用作了一场讲演。 7.(表示主格关系) We waited for the arrival of the next bus. 我们等待下一班汽车的到来。

I have the complete works of Shakespeare. 我有莎士比亚全集。 8.来自...的;出自 He was a graduate of the University of Hawaii. 他是夏威夷大学的毕业生。 9.因为 Her son died of hepatitis. 她儿子因患肝炎而死。 10.在...方面 My aunt is hard of hearing. 我姑妈耳朵有点聋。 11.【美】(时间)在...之前 12.(表示具有某种性质) It is a matter of importance. 这是一件重要的事。 For 1.为,为了 They fought for national independence. 他们为民族独立而战。 This letter is for you. 这是你的信。

双宾语 to for的用法

1.两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for：(1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如：do sb a favour＝do a favour for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害

for和of的用法

for的用法： 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如:

I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如:

for和to区别

1.表示各种“目的”，用for （1）What do you study English for 你为什么要学英语？ （2）went to france for holiday. 她到法国度假去了。 （3）These books are written for pupils. 这些书是为学生些的。 （4）hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．“对于”用for （1）She has a liking for painting. 她爱好绘画。 （2）She had a natural gift for teaching. 她对教学有天赋/ 3．表示“赞成、同情”，用for （1）Are you for the idea or against it 你是支持还是反对这个想法？ （2）He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 （3）I felt deeply sorry for my friend who was very ill. 4. 表示“因为，由于”（常有较活译法），用for （1）Thank you for coming. 谢谢你来。

（2）France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，“对于（某人），对…来说”，（多和形容词连用），用介词to，不用for. （1）He said that money was not important to him. 他说钱对他并不重要。 （2）To her it was rather unusual. 对她来说这是相当不寻常的。 （3）They are cruel to animals. 他们对动物很残忍。 6．和fit, good, bad, useful, suitable 等形容词连用，表示“适宜，适合”，用for。（1）Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 （2）Exercises are good for health. 锻炼有益于健康。 （3）Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 （4）You are not suited for the kind of work you are doing. 7. 表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 （1）It would be best for you to write to him. （2） The simple thing is for him to resign at once.

英语形容词和of for 的用法

加入收藏夹 主题： 介词试题It’s + 形容词 + of sb. to do sth.和It’s + 形容词 + for sb. to do sth.的用法区别。 内容： It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 提交人：杨天若时间：1/23/2008 20:5:54 主题：for 与of 的辨别 内容：It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 答：选A 解析：该题考查的句型It’s + 形容词+ of sb. to do sth.和It’s +形容词+ for sb. to do sth.的用法区别。 “It’s + 形容词+ to do sth.”中常用of或for引出不定式的行为者，究竟用of sb.还是用for sb.，取决于前面的形容词。 1) 若形容词是描述不定式行为者的性格、品质的，如kind，good，nice，right，wrong，clever，careless，polite，foolish等，用of sb. 例： It’s very kind of you to help me. 你能帮我，真好。 It’s clever of you to work out the maths problem. 你真聪明，解出了这道数学题。 2) 若形容词仅仅是描述事物，不是对不定式行为者的品格进行评价，用for sb.，这类形容词有difficult，easy，hard，important，dangerous，（im）possible等。例： It’s very dangerous for children to cross the busy street. 对孩子们来说，穿过繁忙的街道很危险。 It’s difficult for u s to finish the work. 对我们来说，完成这项工作很困难。 for 与of 的辨别方法： 用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for. 如： You are nice.(通顺，所以应用of)。 He is hard.(人是困难的，不通，因此应用for.) 由此可知，该题的正确答案应该为A项。 提交人：f7_liyf 时间：1/24/2008 11:18:42

双宾语tofor的用法

1. 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for： (1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如： do sb a favou r do a favour for sb 帮某人的忙 do sb harnn= do harm to sb 对某人有害

to和for的用法有什么不同(一)

to和for的用法有什么不同（一） 一、引出间接宾语时的区别 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for，具体应注意以下三种情况： 1. 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. 2. 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose, prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes?

正：Can you spare a few minutes for me? 3. 有的动词由于用法和含义不同，用介词to 或for 都是可能的。如： do sb a favor＝do a favor for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害 在有的情况下，可能既不用for 也不用to，而用其他的介词。如： play sb a trick＝play a trick on sb 作弄某人 请比较： play sb some folk songs＝play some folk songs for sb 给某人演奏民歌 有时同一个动词，由于用法不同，所搭配的介词也可能不同，如leave sbsth 这一结构，若表示一般意义的为某人留下某物，则用介词for 引出间接宾语，即说leave sth for sb；若表示某人死后遗留下某物，则用介词to 引出间接宾语，即说leave sth to sb。如： Would you like to leave him a message? / Would you like to leave a message for him? 你要不要给他留个话？ Her father left her a large fortune. / Her father left a large fortune to her. 她父亲死后给她留下了一大笔财产。 二、表示目标或方向的区别 两者均可表示目标、目的地、方向等，此时也要根据不同动词分别对待。如： 1. 在come, go, walk, move, fly, ride, drive, march, return 等动词之后通常用介词to 表示目标或目的地。如： He has gone to Shanghai. 他到上海去了。 They walked to a river. 他们走到一条河边。

keep的用法及of 、for sb.句型区别

keep的用法 1. 用作及物动词 ①意为"保存；保留；保持；保守"。如： Could you keep these letters for me, please? 你能替我保存这些信吗？ ②意为"遵守；维护"。如： Everyone must keep the rules. 人人必须遵守规章制度。 The teacher is keeping order in class.老师正在课堂上维持秩序。 ③意为"使……保持某种(状态、位置或动作等)"。这时要在keep的宾语后接补足语，构 成复合宾语。其中宾语补足语通常由形容词、副词、介词短语、现在分词和过去分词等充当。如： 例：We should keep our classroom clean and tidy.(形容词) 我们应保持教室整洁干净。 You'd better keep the child away from the fire.(副词)你最好让孩子离火远一点。 The bad weather keeps us inside the house.(介词短语)坏天气使我们不能出门。 Don't keep me waiting for long.(现在分词)别让我等太久。 The other students in the class keep their eyes closed.(过去分词) 班上其他同学都闭着眼睛。 2. 用作连系动词 构成系表结构：keep＋表语，意为"保持，继续(处于某种状态)"。其中表语可用形容词、副词、介词短语等充当。如： 例：You must look after yourself and keep healthy.(形容词) 你必须照顾好自己，保持身体健康。 Keep off the grass.(副词)请勿践踏草地。 Traffic in Britain keeps to the left.(介词短语)英国的交通是靠左边行驶的。 注意：一般情况下，keep后接形容词较为多见。再如： She knew she must keep calm.她知道她必须保持镇静。 Please keep silent in class.课堂上请保持安静。 3. ①keep doing sth. 意为"继续干某事"，表示不间断地持续干某事，keep后不 能接不定式或表示静止状态的v-ing形式，而必须接延续性的动词。 例：He kept working all day, because he wanted to finish the work on time. 他整天都在不停地工作，因为他想准时完成工作。 Keep passing the ball to each other, and you'll be OK.坚持互相传球，你们就

202X中考英语：to和for的区别与用法.doc

202X中考英语：to和for的区别与用法中考栏目我为考生们整理了“202X中考英语：to和for的区别与用法”，希望能帮到大家，想了解更多考试资讯，本网站的及时更新哦。 202X中考英语：to和for的区别与用法 to和for的区别与用法是什么 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb. 表示对某人有直接影响比如，食物对某人好或者不好就用to; for 表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语? 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。

2.对于 1.She has a liking for painting. 她爱好绘画。 2.She had a natural gift for teaching. 她对教学有天赋。 3.表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法? 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于(常有较活译法) 1.Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5.当事人对某事的主观看法，对于(某人)，对?来说(多和形容词连用)用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。

to of和for的区别

to , of 和for的区别 1.to有到的意思，常常和go，come，get连用引出地点。Go to school , go to the shop , go to the cinema. 常见的短语：the way to 去---的路 On one’s way to 在某人去---的路上 以上的用法中，当地点是副词home，here，there等是to 要去掉。如：get home，the way here To后跟动词原形，是不定式的标志 It is +形容词+(for/of +人+)to do sth.(括号内部分可以省略) It is easy for me to learn English. It is very kind of you to lend me your money. 当形容词表示人的行为特征时用of表示to do的性质时用for Want, hope ,decide, plan , try , fail等词后跟to do I want to join the swimming club. Would like to do I’d like to play basketball with them. It is time to have a break. Next to , close to , from ---to--- 2.for 为，表示目的。 Thank you for Buy sth for sb =buy sb sth It is time for bed. Here is a letter for you.

I will study for our country. 3.of表示所属关系意思是：---的 a map of the world a friend of mine

for和of引导的不定式结构的区别

for和of引导的不定式结构的区别 不定式是一种非谓语动词，不能单独作谓语，因此没有语法上的主语。但由于不定式表示的是动作，在意义上可以有它的主体。我们称之为逻辑主语。 提起不定式逻辑主语，人们首先想到的会是“for+名词（宾格代词）+不定式”的复合结构。如：It is important for us to study English well．然而，有时不定式的逻辑主语须要用“of+名词（代词宾格）”才行。例如：It is kind of you to help me．而不能说：It is kind for you to help me．在选择介词“for”还是“of”时，人们往往总是凭感觉而定。有时受习惯影响，多选介词“for”。于是常出现这样的错误：It was careless for him to lose his way．It is cruel for you to do so．由于众多语法书对这种结构中使用“for”与“of”的区别介绍甚少，一些人对其概念认识尚不完全清楚，笔者认为有必要就这一问题作些探讨与介绍。 一、在句中的语法作用不同 a．不定式for结构在句中可以作主、宾、表、定、状、同位语： 1．It is easy for Tom to do this work．（主语）汤姆做此工作是容易的。 2．I'd like for him to come here．（宾语）我喜欢他来这里。 3．His idea is for us to travel in two different groups．（表语）他的想法是：我们分成两组旅行。 4．Have you heard about the plan for you to go abroad．（定语）你听到让你出国的计划吗？ 5．The word is too difficult for him to pronounce well．（状语）这单词太难，他念不准。 6．In the most schools，it is the custom for the headmaster to declare the newterm start．在大部分学校，校长宣布新学期开始是一个习惯。 b．不定式of结构只能在句中作主语。 1．It was careless of him to leave his umbrella in the train．他把伞丢在火车上真是太粗心了。 2．It is awfully good of you to come to see me off at the station．谢谢你来车站送我。 二、逻辑主语的名词有所不同

of和for的用法

for 表原因、目的 of 表从属关系 介词of的用法 （1）所有关系 this is a picture of a classroom （2）部分关系 a piece of paper a cup of tea a glass of water a bottle of milk what kind of football，american of soccer？ （3）描写关系 a man of thirty 三十岁的人 a man of shanghai 上海人 （4）承受动作 the exploitation of man by man．人对人的剥削。 （5）同位关系 it was a cold spring morning in the city of london in england． （6）关于，对于 what do you think of chinese food？ 你觉得中国食品怎么样？ 介词for 的用法小结 1. 表示“当作、作为”。如: i like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。what will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: thank you for helping me with my english. 谢谢你帮我学习英语。 thank you for your last letter. 谢谢你上次的来信。 thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如:

介词for和to用法完全归纳

介词for用法完全归纳 ？ 本站特约作者陈根花 ？ 用法1：(表目的)为了。如： They went out for a walk. 他们出去散步了。 What did you do that for 你干吗这样做？ That’s what we’re here for. 这正是我们来的目的。 What’s she gone for this time 她这次去干什么去了？ He was waiting for the bus. 他在等公共汽车。 【用法说明】在通常情况下，英语不用 for doing sth 来表示目的。如： 他去那儿看他叔叔。 误：He went there for seeing his uncle. 正：He went there to see his uncle. 但是，若一个动名词已名词化，则可与 for 连用表目的。如： He went there for swimming. 他去那儿游泳。(swimming 已名词化) 注意：若不是表目的，而是表原因、用途等，则其后可接动名词。(见下面的有关用法) 用法2：(表利益)为，为了。如： What can I do for you 你想要我什么？ We study hard for our motherland. 我们为祖国努力学习。 Would you please carry this for me 请你替我提这个东西好吗？ Do more exercise for the good of your health. 为了健康你要多运动。【用法说明】(1) 有些后接双宾语的动词(如 buy, choose, cook, fetch, find, get, order, prepare, sing, spare 等)，当双宾语易位时，通常用 for 来引出间接宾语，表示间接宾语为受益者。如： She made her daughter a dress. / She made a dress for her daughter. 她为她女儿做了件连衣裙。 He cooked us some potatoes. / He cooked some potatoes for us. 他为我们煮了些土豆。 注意，类似下面这样的句子必须用 for： He bought a new chair for the office. 他为办公室买了张新办公椅。 (2) 注意不要按汉语字面意思，在一些及物动词后误加介词 for： 他们决定在电视上为他们的新产品打广告。 误：They decided toadvertise for their new product on TV. 正：They decided to advertise their new product on TV. 注：advertise 可用作及物或不及物动词，但含义不同：advertise sth＝为卖出某物而打广告；advertise for sth＝为寻找某物而打广告。如：advertise for a job=登广告求职。由于受汉语“为”的影响，而此处误加了介词 for。类似地，汉语中的“为人民服务”，说成英语是 serve the people，而不是 serve for the people，“为某人的死报仇”，说成英语是avenge sb’s death，而不是 avenge for sb’s death，等等。