句子的种类

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： Dont move. Dont be late.2） 第二种祈使句以let开头。 Let 的反意疑问句 a. Lets 包括说话者 Lets have another try，shall we / shant we? = Shall we have another try? b. Let us 不包括说话者 Let us have another try，will you / wont you? = Will you please let us have another try? 否定结构： Lets not talk of that matter. Let us not talk of that matter.