祈使句有哪些特点?——Alice,you do the washing-up after the party,will

祈使句有哪些特点?
——Alice,you do the washing-up after the party,will you?
题干中“you do the washing-up after the party"为什么是祈使句?

祈使句
祈使句表示请求、命令、建议等等.谓语动词一律用原形.句子中通常不用主语,句末用惊叹号或者句号,用降调.
1含有第二人称主语的祈使句
Be careful!小心!
Don''t make such a noise.不要这么吵.
1.肯定的祈使句
a.句型：动词原形～.（省略主语）
Stand up.起立.
Be quiet,please.请安静.
b.有时,为了加强语气,可以在动词之前加do
Do sit down.
务必请坐.
Do study hard.
一定要努力学习.
比较
祈使句和陈述句陈述句：
You sit down.
你坐下来.
祈使句：
Sit down.坐下
（省略主语you）
c.用客气的语气表示祈使句时,可在句首或句尾加上please,但如果在句尾加please,那在please之前一定要加一个逗号“,”.
Go this way,please.
请这边走.
d.祈使句中如果有唤语,一定要用逗号“,”隔开,放在句首或句尾.
Li Ming,come here.
李明,过来.
Come here,Li Ming.
过来,李明.
2.否定的祈使句
句型：Don''t +动词原形～
Don''t swim in the river.
别在河里游泳.
Don''t be late.别迟到.
Please don''t be noisy.
请不要大声喧哗.
注意
表示禁止时,尤其是标语等也可用“No+动名词”来表示.
No smoking.
禁止吸烟.
No parking.
禁止停车.
句型转换
祈使句与陈述句的改写
1．祈使句=You must …（陈述句）
Come here .过来.
=You must come here .
你必须过来.
Don''t do that again.
你一定不可以再那样做了.
2．Please +祈使句=Will you (please) （陈述句）
Please help me .请帮帮我.
=Will you (please) help me?
你愿意帮我的忙吗?
Come here on time ,please .请准时到这儿.
=Will you (please) come here on time
请你准时到好吗?
2含有第一、第三人称主语的祈使句
Let''s say good-by here.
我们在此道别吧.
Don''t let him do that again.
别让他再那么做了.
1.肯定的祈使句
句型：·Let+第一人称（me,us）～.
·Let+第三人称代词（宾格：him,her,it,them）或名词～.
Let''s go at once.
咱们马上动身吧.
Let me try again.
让我再试试.
Let Tom go there himself.
让汤姆自己去那儿.
注意
Let''s包括对方,Let us不包括对方.反意疑问句时最明显.
Let''s go,shall we?
咱们去吧,怎么样?
Let us go,will you?
让我们去吧,行吗?
（征求对方的意见）
2.否定的祈使句
句型：·Let''s（us,me）+not +动词原形～.
·Don''t let +第三人称代词的宾格或名词+动词原形.
Let''s not say anything about it.
对于这件事,咱们什么也不要说.
Don''t let them play with fire.
别让他们玩火.
句型转换
祈使句有时相当一个if引导的条件状语从句.
祈使句：Use your head and you''ll find a way.
条件句：If you use your head,you''ll find a way.
如果你动动脑筋,你就会找到方法.
注意
回答Let''s～的反意疑问句句型时,肯定时用Yes,let''s.否定时用NO,let''s not.
祈使句变反意疑问句的方法：
祈使句后的反意疑问句形式
a,Let's表示说话人向对方提出建议,简短问句的主语用 we表示,问句用 shall we或 shan't we 如:Let's have a cup of tea ,shall we (shan't we)
b,Let me或 Let us表示听话人提出请求,问句用 will you或 won't you .
Let me have a rest ,will you (won't you )
c,其它的祈使句后可以加一个简短问句,使语气变得客气一些.
如:Have a rest ,will you
Stand up ,will (won't) you
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.