I. 要点
表示说的话不是事实，或者是不可能发生的情况，而是一种愿望、建议或与事实相反的假设等。一般常用于正式的书面语中。
1、 虚拟语气的构成
情景 条件从句的谓语动词 主句的谓语动词
与现在事实相反 动词过去式 (be要用were) should
+动词原形
would
与过去事实相反 had +过去分词 should
+have+过去分词
would
与将来事实相反 1、动词过去时
2、should +动词原形
3、were to +动词原形 should
+动词原形
would
注：如果条件从句谓语动词包含有were或had, should, could有时可将if省去, 但要倒装。如：
Had you (If you had) invited us, we would have come to your party.
2、 虚拟语气在各种从句的应用
(1) 在主语从句中用来表示惊奇、惋惜、理应如此等，其谓语形式是"should(可省) +动词原形"，常用于以下三种句型中。
句型一：It is necessary (important, natural, strange, etc) that…
句型二：It is a pity (a shame, no wonder, etc) that…
句型三：It is suggested (requested, proposed, desired, etc) that…
如： It is strange that he (should) have done that.
It is a pity that he (should) be so careless.
It is requested that we (should) be so careless.
(2) 在宾语从句中用于suggest, propose, move, insist, desire, demand, request, order, command等动词后的宾语从句中，表间接的命令和建议。其谓语形式是"(should)+动词原形"。如：
I suggest that we (should) go swimming.
(3) 在表语从句中，表示间接的命令，要求、请求、建议、决定等，主句中的主语通常是suggestion, proposal, request, orders, idea等。从句谓语形式是"(should)+动词原形"。如：
His suggestion is that we (should) leave at once.
(4) 在同位语从句中，谓语形式是"(should)+动词原形"。如：
We received order that the work be done at once.
(5) 在It is time that…句型中，其谓语动词形式是"动词的过去式"或
"should +动词原形",should不可省。如：It's time (that) we went ( should go) to school.
II. 例题
例1 We had hoped that he ____ longer.
A stays B have stayed C stayed D would stay
解析：该题正确答案为D。had hoped表示"本希望"，同样用法的动词还有think, expect等，后面的句子需用虚拟语气
例2 "Mary wants to see you today".
"I would rather she ____ tomorrow than today."
A comes B came C should come D will come
解析：该题正确答案为B。would rather后面的从句需用虚拟语气，用动词过去时表示。www.examw.com
例3 Had she been older, she ____ it better.
A had done B might have done C might do D would do
解析：Had she been older = If she had been old. 故该题正确答案为B。
