1. 与现在事实相反的虚拟：
If + did / were + ..., ... would/ should/ could/ might + do （动词原形）
If I were you, I would go abroad at once. (I am not you.)
If he knew it now, he could help me. (He doesn't know it now.)

2. 与过去事实相反的虚拟：
If + had done + ..., ... would (might) have done ...
If I had known your telephone number yesterday, I would have phoned you. (I didn't know your telephone number.)
If you had come here a little earlier just now, you might have met her. (You didn't come here earlier.)

3. 与将来事实相反的虚拟：
(1) If + should + v., ... would + v. （可能性很小）（译作“万一”）
If it should rain tomorrow, you could stay at home.
If I should fail, what should Ido?

(2) If + did / were to + v ..., would + v. （完全不可能）
If the sun were to rise in the west, I would lend you the money.
If you finished it in 3 minutes, I would give you my car.

4. 特殊重点

［简单联想记忆］：

● 下列动词后的“宾语从句”中需要用虚拟形式，即should + 动词原形，shoud在美国英语中要省略（TOEFL语法考点）。此类常见的动词有：order, ask, decide, demand, require, recommend, suggest（建议）, insist（坚决要求）, advise, etc.
He suggested that we (should) help them with English.
The teacher ordered that the homework (should) be finished within half an hour.

● 下列名词后的同位语从句中要用“should + 动词原形”（should可省去）的虚拟。此类常见的名词有：suggestion, order, request, demand, importance, proposal.
He made a suggestion that we (should) have a fancy dress party.
I think it is a thing of importance that it (should) be done soon.

● It is / was important / necessary / natural / essential / advisable / strange / surprising, ect. + that +主语+ should + v.
It is strange that you should say such a thing.
It was important that you should tell me all the information.

● wish后的宾语从句中，as if 后的状语从句中，须用下列的虚拟形式：
主 + wish+ (that) + 主 + did / were（指现在）
had done（指过去）
would+ v.（指将来）
I wish that I met my uncle now.
I wish I had met my uncle yesterday.
I wish I could meet my uncle tomorrow.

● It is (high) time that ... + did / were ...
It is time that you went to bed.

● would rather that ... + did / were ...
I would rather that you were not here now.

● would sooner that ... + did / were ...
I would sooner that you got up earlier.
I would sooner that you were not my brother.

There are special nightmares for the daytime sleeper: little nervous dreams tossed into some brief restless moments of unconsciousness and breaking through the surface of the mind to become confused at once with the horror of some waking vision. Such are these awakenings, like an awakening in the grave, when one opens one’s eyes, stretched out rigid with clenched hands, waiting for some misery to declare itself; but for a long time it lies to suffocation upon the chest and utters no word.

Under the Net by Iris Murdoch

英语语法总结：虚拟语气

1. 与现在事实相反的虚拟：
If + did / were + ..., ... would/ should/ could/ might + do （动词原形）
If I were you, I would go abroad at once. (I am not you.)
If he knew it now, he could help me. (He doesn't know it now.)

2. 与过去事实相反的虚拟：
If + had done + ..., ... would (might) have done ...
If I had known your telephone number yesterday, I would have phoned you. (I didn't know your telephone number.)
If you had come here a little earlier just now, you might have met her. (You didn't come here earlier.)

3. 与将来事实相反的虚拟：
(1) If + should + v., ... would + v. （可能性很小）（译作“万一”）
If it should rain tomorrow, you could stay at home.
If I should fail, what should Ido?

(2) If + did / were to + v ..., would + v. （完全不可能）
If the sun were to rise in the west, I would lend you the money.
If you finished it in 3 minutes, I would give you my car.

4. 特殊重点

［简单联想记忆］：

● 下列动词后的“宾语从句”中需要用虚拟形式，即should + 动词原形，shoud在美国英语中要省略（TOEFL语法考点）。此类常见的动词有：order, ask, decide, demand, require, recommend, suggest（建议）, insist（坚决要求）, advise, etc.
He suggested that we (should) help them with English.
The teacher ordered that the homework (should) be finished within half an hour.

● 下列名词后的同位语从句中要用“should + 动词原形”（should可省去）的虚拟。此类常见的名词有：suggestion, order, request, demand, importance, proposal.
He made a suggestion that we (should) have a fancy dress party.
I think it is a thing of importance that it (should) be done soon.

● It is / was important / necessary / natural / essential / advisable / strange / surprising, ect. + that +主语+ should + v.
It is strange that you should say such a thing.
It was important that you should tell me all the information.

● wish后的宾语从句中，as if 后的状语从句中，须用下列的虚拟形式：
主 + wish+ (that) + 主 + did / were（指现在）
had done（指过去）
would+ v.（指将来）
I wish that I met my uncle now.
I wish I had met my uncle yesterday.
I wish I could meet my uncle tomorrow.

● It is (high) time that ... + did / were ...
It is time that you went to bed.

● would rather that ... + did / were ...
I would rather that you were not here now.

● would sooner that ... + did / were ...
I would sooner that you got up earlier.
I would sooner that you were not my brother.