虚拟语气
历次考题的高频考点，请务必熟练掌握
带有if条件句的虚拟语气句
if句的谓语形式 主句谓语形式
对过去假设 had done would have done
对现在假设 一般过去式 would+动词原形
(be 用were)
对将来假设 一般过去式 would+动词原形
were to + 动词原形
should +动词原形
wish引导的宾从
现在的情况 过去式
过去的情况 had+过去分词/
could have done
将来的情况 would/could+动词原形
He wishes that he had studied hard in university.
I wish I could pass the exam tomorrow.
would rather that
现在将来的情况 用过去式
过去的情况 用had+过去分词
I would rather that you didn’t tell me the answer now.
I would rather that you didn’t go there tomorrow.
I would rather that you hadn’t been involved in the accident last month.
It’s (about/almost/high) time that …
从句用一般过去式
It’s time that you went to bed.
it’s time that class began.
if条件句,可以省略if,助动词were, had, should 要前置，形成倒装语序。
Had her father a lot of money, he would send her abroad.
Were it rainy, we would buy an umbrella.
Should the Black Death (黑死病) reappear, what should we do?
“Were it not for/Had it not been for+宾语” 表示假设条件。
a.Were it not for their assistance, we couldn’t have
got over the difficulties.
b. Had it not been for your help, we wouldn’t have been able to pass the exam.
as if (as though) 引导的比较状语从句中谓语动词一 般用were / had+过去分词表虚拟。
He speaks English so well as if he were English.
She looked as if she had succeeded.
常见的引导宾语从句须用虚拟语气的动词
advise, desire, maintain, command, demand, direct(命令), insist, order, prefer, propose, request, require, resolve, suggest, urge，recommend 等
常见的引导同位语从句或表语从句须用虚拟语气的名词
advice, command, desire, order, demand, recommendation, suggestion, insistence, proposal, request, requirement等;
用在主语从句中时其结构通常为“It is/was + 形容词或过去分词+主语从句(用虚拟语气)”
常见的这类形容词、分词还有：advisable(合理的), necessary, urgent(紧急的), appropriate(合适的), compulsory(强制的), crucial(紧要关头的)，desirable(理想的), essential(必要的), important(重要的), natural(自然的), proper，preferable(更好的), strange, vital(至关重要的), demanded(要求的), required(要求的), suggested(建议的), desired(希望的)等。