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。
We all hope for success. 我们都盼望成功。
Are you coming in for some tea? 你要不要进来喝点茶？
用法5：给(某人)，供(某人)用。如：
That's for you. 这是给你的。
Here is a letter for you. 这是你的信。
Have you room for me there? 你那边能给我腾出点地方吗？
用法6：(表原因、理由)因为，由于。如：
I am sorry for it. 对不起。
Thank you for coming to see me. 谢谢你来看我。
You can't see the wood for the trees. 你只见树木，不见森林。
He is famous for his poems. 他因为他的诗出名。
He was sent to prison for robbery. 他因为抢劫而坐牢。
I couldn't speak for laughing. 我笑得说不出话来。
He couldn't sleep for joy. 他高兴得不能入睡。
For several reasons, I'd rather not meet her. 由于种种原因，我宁愿不见她。
【用法说明】有些表原因的特殊结构不宜用介词 for 来引出，而用其他介词。如：
他由于努力工作而加了工资。
误：For the result of his hard work, he got a pay rise.
正：As a [the] result of his hard work, he got a pay rise.
注：as a [the] result of 是习语，意为“由于……的结果”。
因为母亲不在家，她只好自己做饭。
误：For Mother (being) away, she had to cook the meal herself.
正：With Mother (being) away, she had to cook the meal herself.
注：“with 宾语 宾语补足语”可用来表示原因，此时的 with 不能换成 for。类似地，下例中的 with 也不能换成 for：
With all this work to do, I don't know if I'll have time to go out. 有这么多工作要做，我不知是否有时间出去。
我们祝贺你的成功。
误：We congratulate you for your success.
正：We congratulate you on your success.
注：congratulate 后习惯上接介词 on 表示原因。
用法7：(表目标、去向)去。如：
Is this bus for Chicago? 这辆公共汽车开往芝加哥吗？
They'll leave for Beijing tomorrow. 明天他们动身去北京。
They set off for the shops. 他们买东西去了。
Is this the train for Shanghai? 这是开往上海的火车吗？
Passengers for Tianjing must change at Beijing. 去天津的旅客必须在北京换车。
【用法说明】比较 for 与 to，两者均可表示目的地，注意以下区别：
for 通常与 leave, start, set out, set off, head, steer, depart, be bound, be destined 等动词连用，而 to 则通常与 come, drive, fly, get, go, lead, march, move, return, ride, run, travel, walk 等动词连用。如：
We departed for London at 10 am. 我们上午10点动身去伦敦。
Then we drove to the station. 然后我们就开车去了车站。
有时，同一个动词(如 sail)两者均可连用，但含义稍有差别：用 for 通常只表示向着某目的地那个方向，并不强调到达的意思；而 to 含有到达某目的地的意思。如：
They sailed for Shanghai. 他们开船驶往广州。
They sailed to Shanghai. 他们开船驶至广州。
若与名词连用，也有类似区别。如：
There will be a train for Wuhan. 有开往武汉的火车。(仅表示向武汉方向，但在武汉未必是停靠站)
There will be a train to Wuhan. 有开往武汉的火车。(开往武汉方向，且在武汉停靠)(R56)
顺便说一句，也有的辞书持几乎相反的观点，认为 for 与 to 表示目的地时，for 表示的是预定目的地，而to 表示的是假设将会到达的目的地。
用法8：(表时间、距离、数量等)达，计。如：
I'm going away for a few days. 我要走开几天。
I've been here for ten years. 我来这儿有10年了。
He walked for ten miles. 他走了10英里路。
The shop sent me a bill for $50. 商店给我送来了一张50美元的账单。
【用法说明】for 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。
用法9：对，对于。如：
Eggs are good for you. 鸡蛋对你有好处。
Reading in bed is bad for your eyes. 躺在床上看书对你的眼睛不好。
Fortunately for me, the train was also late. 我很走运，火车也晚点了。
【用法说明】关于 for 与 to 表示“对……来说”时的区别，参见 to。
用法10：(表适合)适于，适合。如：
Do you have any books for children? 你有适合小孩子看的书吗？
He is the very person for the work. 他是最适合做这工作的人。
It's a good place for a camp. 那是个露营的好地方。
She bought some clothes for winter. 她买了些冬天穿的衣服。
用法11：(表交换)换，以……作交换。如：
He gave her some magazines for her dictionary. 他用几本杂志换她的字典。
She bought the skirt for $50. 她花了50美元买这条裙子。
I bought a pound of apples for 70 cents. 我花了七角钱买了一磅苹果。
Don't translate word for word. 不要逐字硬译。
用法12：作为，当作。如：
Don't take him for a fool. 别把他当傻瓜。
He mistook a rope for a snake. 他把一条绳子误认为是蛇。
He knew that for a fact. 他知道那是事实。
The missing persons were given up for dead. 大家都认为那些失踪的人已死了。
【用法说明】用于此义时，有时相当于 as, to be, as being，但要注意不同句型的搭配习惯。如：
I took him for an honest man. / I took him to be honest. 我看他为人老实。
It was built for [as] a pleasure boat. 这船建作游艇之用。
比较：
He took her smile for agreement. 他把她的微笑视为同意。
Will you take me as your partner? 你把我看作你的合伙人好吗？
按传统语法，take…for… 通常指误认为是……，而 take…as [to be] 则主要指正确地认为是……。但在现代英语中，有时并未完全遵守此规则。
但是与 mistake 连用的则通常是 for 而不是 as。如：
We mistook the house for a hotel. 我们把那房子误以为旅馆。
用法13：(表支持、赞成)支持，赞成。如：
Are you for or against the plan？你是支持还是反对这个计划？
I'm all for the young enjoying themselves. 我完全赞成年轻人多玩玩。
用法14：(表基准)就……来说，以……而言，作为。如：
He's done well for a beginner. 作为新手，他干得很好。
He is heavy for a small boy. 作为一个小男孩而言，他的身体算重的了。
She was short for her age. 就她的年龄来说，个子是矮了点。
The day is cool for July. 在7月里这样的日子算是凉快的了。
用法15：(表比例)每……就……。如：
Plant three trees for every one that is cut down. 每砍一棵树要种三棵树。
He has one enemy for a hundred friends. 他的敌人与朋友之比为一比一百。
For every five who passed, there were two who failed. 每5个人及格，就有2个不及格。
For every mistake you make, you'll lose half a mark. 你每犯一个错误，就要扣去半分。
【用法说明】用于此义时，通常与 each, every 或数词连用。
用法16：代表，代替，代理。如：
What's the English for “中国”? 英语里“中国”怎么说？
What's the “C” for in “BBC”? BBC中的C代表什么？
Red is for danger. 红色代表危险。
Let me do it for you. 让我替你做吧。
The lawyer acted for him during the trial. 在审案期间由律师代表他行事。
用法17：(表安排的时间)在，于。如：
The appointment is for 10:30. 约会定在十点半。
We've invited our guests for 7 o'clock. 我们已邀请我们的客人7点钟来。
We've booked our holiday for the second week in July. 我们的假期安排在七月份的第二个星期。
The next meeting was arranged for the tenth of May. 下次会议已定于5月10日举行。
【用法说明】用于此义时，for 主要指安排或约定的时间，所以像下面两例中的介词 at，in 就不能换成 for。如：
He gets up at six every day. 他每天6点钟起床。
He was born in September, 1988. 他出生于1988年9月。
用法18：(表让步)尽管，虽然。如：
For all his money, he's a very lonely man. 他虽然富有，可是非常寂寞。
For all his efforts, he didn't succeed. 尽管他做了很多努力，却仍然没有成功。
I love you, for all your shortcomings. 尽管你有很多缺点，但我仍然爱你。
【用法说明】用于此义时，通常与 all 连用。(见上例)
用法19：(与不定式连用引出逻辑上的主语)。如：
It is for you to decide. 该由你来决定。
All I want is for us to be together. 我希望的只是我们能在一起。
Is there any need for me to go? 我有没有必要去？
He spoke too fast for her to follow. 他说得太快，她跟不上。
It is a great pity for him to leave here so soon. 他这么快就离开这里真是遗憾。
It is dangerous for a small child to cross the road alone. 小孩子自己过马路很危险。
For a bridge to collapse like that is unbelievable. 一座桥像那样倒塌是不可想像的。
【用法说明】(1) 下面两句同义，但以第一句为普通。如：
老人快跑是危险的。
正：It is dangerous for an old man to run fast.
正：For an old man to run fast is dangerous.
(2) 有时可表目的。如：
I've sent my coat away for it to be cleaned. 我把外衣送去洗了。
For sales to increase, we must lower our prices. 为了增加销量，我们必须降低价格。
(3) 有时用于 than 后引出不定式的逻辑主语。如：
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。
