for 表原因、目的
of 表
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
（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
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
?
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。
请讲一下BY的用法 是不是.
1）表示以一般的方法或方式。如：
No one in those days could live by writing poems.
（2）表示传达、传递的方式或煤介。如：
How did you send the letter, by airmail or by ordinary mail?
（3）表示用交通工具、通讯工具后接名词单数，不加冠词。如：
He came by train, but his wife came by bus.
注意下面两句的区别：
Did you come by train?
Did you come in his car / on my bike?
“by +抽象名词”构成的词组有：by accident / by chance / by diligence / by effort / by force / by heart / by luck / by mistake / by hard work.
by 多数是通过什么方式 eg.by doing sth.
for 是为了 表原因或对象