for
1.for two hours, for three weeks, for many years, for several miles等表达方式里的for有时省去，但在正式些的文字里最好不省去。有下面两点该注意：
（1）在句首通常不省去，如For two hours he had been waiting里的For通常不省。
（2）下面第一句可能有两个意思，第二句只有一个意思：
I have not studied English for two years. （1.我已经有两年不学习英语了。2.我学习英语以来还不满两年。）
I have not studied English two years. （我学习英语以来还不满两年。）
2.注意下面各句的意思：
This is the best book I have read for a long time. （1.这是过去的很长一段时期里我所读过的最好的书。2.我好久不曾读过这样的好书了。不作“这是我所读了好久的最好的书”解。）
This is the first book I have read for five weeks. （1.这是在过去的五星期里我所读过的第一本书。2.自从五星期以来我只读过这本书。不作“这是我所读了五星期的第一本书”解。）
I have not read any book for a long time. （我好久不读书了。不作“我不曾把任何书读了好久”解。）
I shall not read any book for five weeks. （1.在以后的五星期里我将不读书。2.我将在五星期以后才读书。不作“我将不把任何书读五星期”解。）
3.I have met him three（或four等）times等句子里的three times等表达方式的前面没有for。
4.下面各句都不合习惯：
- I went there for seeing him.
- They will come for hearing the music.
- We work hard for building socialism.
该把for seeing改作to see, for hearing改作to hear, for building改作to build。注意I went there for sightseeing和They will come for pheasant shooting是可以说的，这里的seeing和shooting并不是临时用的动名词。
5.It is shameful for him to do so的结构原来是It is shameful for him, to do so。那for him属于shameful。但渐渐被人看作是It is shameful, for him to do so。那for him形容to do，因而有For him to do so is shameful的结构。又如For anything to happen here is hardly possible和For you to try again would be advisable。
那for...属于前面的词还是属于后面的不定式，有时在全句意思上有出入，如It is dangerous for him, to drive a car是“驾驶汽车对于他是危险的”。It is dangerous, for him to drive a car是“他驾驶汽车对于别人是危险的”。
6.for现在只用作并列连接词。除了在极短的句子里以外，它的前面通常用分号。for用作连接词在口语里很不普通。
7.for可以引导全句，把那全句跟前句相接。例如：We hold that the cause of all the motion and change in the world lies in the material world itself. For the world is by its very nature material. 有时用在自然段落的开首。
8.for既然是并列连接词，所以当用在句首的时候，它把那句子跟前句相接，决不可把它所引导的从句用作那句子里的状语从句，如不可说For I had something to tell him, I went to see him。该改作I went to see him, for I had something to tell him。
9.for有时引导一个插入从句。例如：
- According to relevant regulations, for his mother was the widow of a national hero, he received a good education.
- Tom bought a chain, one of silver gilt, certainly, for he had not the money for a gold one, but of very pretty workmanship.
10.下面四句都不对：
- I am sorry, for I have not answered your letter.
- Excuse me, for I have not answered your letter.
- Forgive me, for I have not answered your letter.
- Pardon me, for I have spoken rudely.
该改作：
- I am sorry that I have not answered your letter.
- Excuse me for not having answered your letter.
- Forgive me for not having answered your letter.
- Pardon me for having spoken rudely（或speaking rudely）.
11.下面各句里的for all...都作“尽管、虽然”解：
- For all that he failed.
- For all his efforts he failed.
- For all he had done he failed.
- For all he had worked hard, he failed.
- For all that he had worked hard, he failed.
第一句和第二句里的all是形容词，第三句里的all是名词，第四句里的for all和第五句里的for all that都可以算作连接词。
12.下面两句里的for后面的过去分词的前面可以说省去了being，但事实上不可加上being：
I took your consent for granted. （1.我假定了你的应许。2.我以为你一定同意。）
He gave himself up（或over）for lost. （他自己想一定没有希望了。）
13.在书的题献（dedication）里一向用To，但近来有用For的。例如：
For
A. J. Brown
