5.lest引导的目的状语从句

由lest引导的目的状语从句带有否定意义，相当于汉语的“免得”、“以防”、“以免”等意义。从句的谓语动词通常带有should。(参见虚拟语气)

The man started by night lest he should be seen by anyone．

此人夜间动身，以免让人看到。

We had to be very careful lest the news should become known early．

我们必须谨慎小心，免得消息过早地走漏出去。

I obeyed her lest she should be angry．

我得顺着她，免得她生气。

提示：

lest引导的目的状语从句常被for fear that，so that．．not或in order that．．not所替代。

I punished the child lest he should make the same mistake．

=I punished the child for fear that he should make the same mistake．

=I punished the child so that he should not make the same mistake．

=I punished the child in order that he should not make the same mistake．

我惩罚了孩子为的是他以后不要犯同样的错误。