enough用作形容词时表示足够的，充分的；在句子中多作定语。用作副词时表示足够，充分；一般放在所修饰的形容词、副词或动词后。用作名词时在句中用作主语或宾语。

一.enough用作形容词

1.enough作形容词时,意思是“足够的,充分的”,在句中多作定语,一般修饰复数名词或不可数名词,可置于所修饰的名词之前,也可置于所修饰的名词之后。后者属于旧式用法。

2.当主语是it或是特定数量时, enough也可用作表语,其后常接for引起的短语或动词不定式。

3.用作定语

（1）～+ n.

We have enough salesmen to cover the area .我们本地区有足够的售货员。

We have enough money to buy a car.我们有足够的钱购买一辆小汽车。

（2）n. +～

The fellow has cheek enough.那家伙脸皮厚。

We don't have time enough to finish the work.我们没有足够的时间去完成这项工作。

4.用作表语

（1）S+be+～

Five men will be quite enough.五个人就足够了。

（2）S+be+～+for n./pron.

Two apples is/are enough for me.两个苹果对于我足够了。

（3）S+be+～+to- v

If each of us kicks in a small amount, it'll be enough to buy things for the party.

我们每一个人捐一点钱的话,就足够买联欢会所需要的东西了。

二.enough用作副词

1.enough用作副词时,意思是“足够,充分”,一般应放在所修饰的形容词、副词或动词的后面。

2.enough还可作“相当地”“还可以地”解,这时在语气上起弱化作用,即语气上比不加enough时为弱。

I don't know him well enough to ask him for help.

我和他不够熟,不便请他帮忙。

He didn't run fast enough to catch the train.

他跑得不够快,没有赶上火车。

三.enough用作名词

enough用作名词表示足够，充分，足量，满足等含义。主要在句中用作主语或宾语。

Not enough is known about this subject.

对这个问题的了解还不够。

I've had enough, thank you.

我吃饱了,谢谢。