一、动词不定式的形式

1.肯定式

2.否定式：not to do sth.或never to do sth.

Take care not to break it.小心别把它打破了。

You were silly not to have locked your car.你没锁车太傻了。

Go in quietly so as not to wake the baby.进去时不要出声，以免把宝宝吵醒。

go in quietly in order not to wake the baby.

He has made it a rule never to cast his net more than three times a day.

他习惯于每天撒网不超过三次。