13.1 祈使句结构
祈使句用以表达命令,要求,请求,劝告等。
1)祈使句有两种类型,一种是以动词原形开头,在动词原形之前加do(但只限于省略第二人称主语的句子)。
Take this seat.
Do be careful.
否定结构:
Don't move.
Don't be late.
2)第二种祈使句以let开头。
Let 的反意疑问句
a.Let's 包括说话者:Let's have another try,shall we/shan't we?= Shall we have another try?
b.Let us 不包括说话者:Let us have another try,will you/won't you?= Will you please let us have another try?
否定结构:
Let's not talk of that matter.
Let us not talk of that matter.