摘要：英语中有三种不同的语气：陈述语气，祈使语气和虚拟语气。所谓的虚拟语气，可以理解为一种礼貌用语，比如需要别人按照你的意愿做一些事(建议、要求、命令)，或者是一些美好愿望，做出一些假设时，就用虚拟语气。

英语中有三种不同的语气：陈述语气，祈使语气和虚拟语气。所谓的虚拟语气，可以理解为一种礼貌用语，比如需要别人按照你的意愿做一些事(建议、要求、命令)，或者是一些美好愿望，做出一些假设时，就用虚拟语气。

今天我们来学习虚拟语气，即should+do一类。

第一大类：（should） + v.(原形)

①表示“建议、愿望、命令”的相关句型

一坚持：insist

二命令：order，command

三建议：advise，suggest，propose，recommend

四要求：require，request，demand，desire（ask, urge, prefer）

跟在这些动词之后的宾语从句用（should）+ do结构

注意：当suggest作“表明”，insist作“坚持说、坚持认为”意思时，则不用虚拟语气。

②当以上词语发生词性变化时，与之相关的名词性从句也用虚拟语气

a. suggestion，proposal，order，request, advice, idea, plan etc.与之有关的表语从句、同位语从句、主语从句

b. It + be + adj./p.p/n. that从句

adj：important, necessary, essential, natural, strange

p.p: desired, suggested, proposed, recommended.

n.: a pity, a shame, a wonder, a must etc.

e.g. They insisted that we (should) go with them.

His proposal is that we (should) get rid of the bad habits.

It is suggested that the meeting (should) be put off till next week.

It is strange that he (should) have acted toward his parents like that.

My idea is that we (should) think it over before accepting it.

It is a pity that he (should) refuse to accept the offer.

③ It’s (high) time + that + should do/did … （(早该)到做某事的时间了）

e.g. It is (high) time (that) we should start out.

④ 目的状语从句中

在 in case, lest, for fear that, in order that, so that 等引导的状语从句中，动词用“could/should/ might/would等+v.(原形)”表示虚拟。

She called him lest he should go out.

They left early for fear that they would meet him.

来源：小天课堂