教你学英语

语句的表达中有些句子虽然含有表示否定意义的词,但整个句子表达的却是肯定的意思.现归纳如下,供同学们学习时参考:
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。