介词of 用法注意1.表示所有关系，用以构成名词的所有格，如the gate of the school（校门），the se cret of success（成功的秘密），等。

注意以下正误表达：正：He is a friend of my father. 他是我父亲的一位朋友。

正：He is a friend of my father’s. 他是我父亲的一位朋友。

正：He is a friend of mine. 他是我的一位朋友。

误：He is a friend of me.以下表达是错误的：误：What’s the name of you?（改为…your name）误：Do you know the father of him?（改为…his father）误：I will show the books of me.（改为…my books）但是以下表达却是对的（of表示动宾关系）：正：I hate the sight of him. 我讨厌看到他。

正：His criticism of her is serious. 他对她的批评是严肃的。

2.与age, shape, size, colour, height, design, weight 等名词连用，可用作表语或定语；其中的介词of 有时可省略。

如：The two boys are (of) the same height. 这两个男孩一样高。

Here is a piece of wood (of) the right size. 这有一块木头，其大小刚好适合。

When I was (of) your age, I lived in the country. 我像你这个年纪的时候，我住在乡下。

3.与某些名词（如help, value, interest, importance等）连用，相当于形容词，可用作定语或表语。

如：It’s not of mu ch value. 这没有多大价值。

This subject is of great interest to me. 这门学科对我来说是很有趣的。

The dictionary is of much help to the students. 这本字典对学生帮助很大。

4.与hear, talk, know, speak 等动词连用，表示一种间接性，大意为“涉及到”。

如：I’ve never heard of anyone doing a thing like that. 我从未听说有人做过那种事。

Mary is talking of looking for another job. 玛丽说起要另找一份工作。

I don’t know the writer, but I know of him. 我不认识这个作家，但我听说过他。

People spoke of their fear as the flood waters rose. 人们说起看到洪水上涨时的恐惧。

5.与表示动作的名词或动名词连用，表示动宾关系。

如：The writing of the letter took me three hours. 写这封信花了我3个小时。

Loss of health is worse than loss of wealth. 失去财富比失去健康更糟。

6.表示比较范围，意为“在……当中”。

如():Of all the choices, this is the best. 在所有选择中，这种最好。

Of the two coats, the black one is the better. 在这两件外套中，这件黑色的更好些。

7.与careless, clever, cruel, foolish, friendly, generous, good, impolite, kind, nice, pol ite, right, rude, selfish, silly, stupid, wise, wrong等表示人的品行和特点的形容词连用，用于It’s+adj.+of sb (to do sth) 句型。

如()：It was kind of him to wait. 多蒙他好心等候。

It was silly of you to believe him. 你相信他是愚蠢的。

It was foolish of me to forget. 我真蠢，竟然忘记了。

It’s unfair of him to criticize me. 他批评我是不公平的。

It was generous of him to pay us. 他付了我们钱，真慷慨。

It was selfish of him not to contribute anything. 他很自私什么也不捐。

It was careless of you to leave your camera in the taxi. 你把照相机留在计程车里实在太不小心了。

介词from 用法注意1.不要根据汉语意思在及物动词后误加介词from。

如：他上个星期离开中国去日本了。

误：He left from China for Japan last week.正：He left Chine for Japan last week.另外，也不要根据汉语意思错用介词from。

如：太阳从东方升起，从西方落下。

误：The sun rises from the east and sets from the west.正：The sun rises in the east and sets in the west.2.from虽然本身是介词，但它有时也可接介词短语作宾语。

如：Choose a book from among these. 从这些书中选一本吧。

A man stepped out from behind the wall. 一个人从墙后走出来。

比较：I took it from the bed. 我从床那儿（或床上）拿的。

I took it from under the bed. 我从床下拿的。

注意，下面一句用了from where（引导非限制性定语从句），而未用from which，其中的where=in the tree，即from where=from in the tree。

如：He hid himself in a tree, from where he could see the enemy in the distance. 他躲在一棵树上，从那儿他可以看到远处的敌人。

3.有时其后可接when, where引导的宾语从句，此时可视为其前省略了the time, the place。

如：He didn’t speak to me from when we moved in. 从我们迁入之时起，他没和我说过话。

From where I stood I could see everything clearly. 从我站的地方我一切都看得清清楚楚。

4.某些由from…to…构成的习语通常不带冠词：from house to house 挨家挨户from hand to hand 从一人之手到他人之手from time to time 不时地from shop to shop 逐店from day to day 一天天地from head to foot 从头至脚, 全身from beginning to end从头至尾from hand to mouth 赚一点吃一点, 仅能糊口from morning to night 从早到晚介词for 用法说明1.后接名词可用来表示目的。

如：What did you do that for? 你干吗这样做？I try to go for a run every day. 我每天都试着跑一跑。

但它习惯上不能后接动名词来表目的，遇此情况可改用不定式发，如：He went there to see his uncle. 他去那儿看他叔叔。

不过，对于已经名词化的动名词，它可以与for连用表目的。

如：He went there for swimming. 他去那儿游泳。

（swimming 已名词化）另外，for doing sth 虽然不用于表目的，但可用于表原因、用途等。

如：Thank you for coming to see me. 谢谢你来看我。

This is a tool that’s used for cutting hedges. 这是一样用来整修篱笆的工具。

2.用于表示时间或距离的长度（尤其是紧跟在动词之后）时，有时可省略。

如：The meeting lasted (for) three days. 会议持续了3天。

They walked (for) fifty miles. 他们走了50英里。

但是，当for短语位于句首或在否定句中时，for 通常不宜省去。

如：For ten years he lived here. 他在这里住过10年。

We have not heard from him for a long time. 我们很久没收到他的来信了。

3.用于for sb to do sth引出不定式的逻辑主语时，该结构可用作主语、表语、宾语、定语、目的状语、结果状语、比较状语等。

如()：For a child to do that job is just inconceivable. 让一个孩子做这项工作真是不可思议。

It is for you to decide. 该由你来决定。

I meant for you to eat, son. 我的意思是要你吃，孩子。

Is there any need for me to go? 我有没有必要去？She opened the door for me to come in. 她开门让我进去。

The box is too heavy for me to carry. 这箱子太重了，我搬不动。

There’s nothing worse than for a person to ill-treat a child. 没有什么比虐待小孩更恶劣的了。

介词by 用法详解1.表示场所，意为“在……旁边”“在……近旁”“在……手边”，此时要注意它与介词near有所不同，即by 表示的距离更“近”。

比较：He lives by the sea. 他住在海滨。

He lives near the sea. 他住在离海不远处。

2.表示动词执行者，主要用于被动语态，此时要注意它与介词with的区别：by 表示动作的主体，with 表示动作者的手段工具。