一、 在含有 cannot 短语的一些句子中。

　　1. cannot help +doing意为"禁不住……"。如:

　　I cannot help laughing. 我禁不住大笑起来。

　　2. cannot but+do; cannot help but + do; cannot choose + do意为"不得不……"。如:

　　He is such an unselfish man. You cannot help but respect him.他是这样一个毫无私心的人.你不得不尊敬他。

　　I cannot but admire his courage. 我不得不佩服他的勇气。

　　3. cannot...too 意为"越……越好"。如:

　　You cannot be too careful.你越仔细越好。

　　二、nobody/nothing/no one...but...意为"不过是……;只……"。如:

　　Nothing but a miracle can save her now. 现在只有出现奇迹她才能得救。

　　三、在表示双重否定的句子中。如:

　　Without water, nothing could live.没有水,什么也活不了。

　　I cannot go without getting my lessons done.不把功课做好,我就不能去。

　　Don't be so careless with your money.花钱要仔细(不要太随便)。

　　四、在一些句型中。

　　1.在not...until句型中.意为"直到……才".如:

　　He didn't come back until late in the evening. 他直到晚上很晚才回来。

　　She didn't arrive until the game had begun. 直到比赛开始她才到。

　　2. 在 not only...but also句型中 .意为"不但……而且"。如:

　　Not only boys but also girls are invited to the party.不但男孩子们,而且女孩子们也被邀请参加宴会。

　　3. 在 no sooner...than; hardly/scarcely/barely...when句型中.意为"一……就"。如:

　　I had no sooner reached home than it began to rain. 我刚到家天就开始下雨了。

　　She had hardly sat down when she heard someone knocking at the door. 她刚坐下来就听见有人敲门.

　　五、在一些短语中。

　　nothing / not much / little to choose between the two(两者差不多);no more than(仅有); no less than...( 有……之多;正好); not a little(很;非常);not the less (还是;仍旧)等。

　　如:

　　There is not much to choose between the two. 两者不相上下。

　　I'm no more than an ordinary worker.  我仅是个普通的工人。