for有很多种用法：
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:
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.
ABOUT
动词+about+sth.
about在此表示“论及,谈起,涉及,着手”等意思：arrange about安排,argue about辩论,ask about询问,bring about带来,chat about闲聊,care about在意,complain about报怨,go about着手,hear about听说,inquire about打听,know about了解,quarrel about争论,read about读到,see about负责处理,set about开始,speak about谈起,talk about谈论,think about考虑,trouble about担心,tell about讲述,worry about着急.现举例说明其中一些短语的用法：
She inquired about my brother.她向我打听有关我兄弟的情况.
I must set about my packing.我必须开始收拾行装.
What are you chatting about?你们在聊什么呢?
be +形容词+about+sth.
about在此意思是“为…,对…”,接表原因的词：be anxious about为…着急,be bad about对…感到不舒服,be busy about忙于…,be careful about小心…,be certain about对…有把握,be concerned about关心…,be crazy about为…发狂,be excited about为…感到激动,be happy about为…而高兴,be mad about为…发疯,be nervous about对…感到紧张,be particular about挑剔…,be pleased about为…兴奋,be strict about对…严格,be thoughtful about对…考虑周到的,be uneasy about为…感受到不安.
请看例句：
What have you been busy about today?今天在忙些什么?
You are certainly very thoughtful about others.你为别人想得太周到了.
I’m strict about such things.对这些事我是很严格的.
注：come about发生,get about（疾病、谣言）流行,turn about转身,leave about到处乱放,lie about随便堆放,put about打扰;传播,put oneself about使…发愁.这些词组中about作副词,此时about不能接宾语.