558　too...to do sth., not too... to do sth.和not...enough to do sth.

1　too+形容词或副词+to do sth. 表示“太……不能”，表示否定含义。

He is too old to work. 他年纪太大，不能工作了。

The book is too difficult to read. 这本书太难，读不懂。

He got up too late to catch the train. 他起得太晚了，没赶上火车。

The girl is too young to look after herself. 这小女孩太小，不能照顾自己。

提示

“too...to”句型本身已具有否定含义，不定式前不可再加not。

The coffee is too hot to drink. （正）咖啡太烫了，不能喝。

The coffee is too hot not to drink. （误）

2　not/never too...to do sth. 为双重否定，表示肯定意义，意为“不太……而能”。

She is not too tired to walk on. 她不是很累，还能继续走。

He is not too old to work. 他年纪不太大，还能工作。

One is never too old to learn. 人们年纪再大也能学习。/活到老，学到老。

比较

The box is too heavy to carry. 这箱子太重，搬不动。

The box is not too heavy to carry. 这箱子不太重，搬得动。

3　not...enough to do sth. 意为“还不够”。

The child is not old enough to go to school. 这孩子还没有到上学的年龄。

The book is not easy enough for her to read. 这本书对她来说不容易读懂。