【例】If I were you, I would buy that house.
If he had time, he should go with you.
【例】If he had taken my advice, he would have succeeded in passing the examination.
【例】If it were to rain tomorrow, the football match would be put off.
【例】If they had worked hard, they would be very tired now.（从句说的是曩昔，主句指的是现在）
【例】I wish it were spring all the year round.
I wish I had known the answer.
I wish I could fly like a bird.
【例】She suggested we (should) leave here at once.
The doctor ordered she should be operated on.
【例】His suggestion that we (should) go to Shanghai is wonderful.
My idea is that they (should) pay 100 dollars.
It is necessary (important，natural，strange，etc.)that we (should) clean the room every day.
It was a pity (a shame，no wonder，etc.)that you (should) be so careless.
It will be desired (suggested，decided，ordered，requested，proposed，etc.)that she (should) finish her homework this afternoon.
【例】It is a pity that you can’t swim.
（1）虚拟口气在as if/as though，even if/even though等引导的表语从句或状语从句中，假如从句表明的动作发作在曩昔，用曩昔完成时；指现在情况，则用一般曩昔时；指将来情况则用曩昔将来时。
【例】He did it as if he were an expert.
Even if she were here, she could not solve the problem.
这种从句常用于句型“It is (high)time (that)．..”中，定语从句的谓语动词用一般曩昔时（be用were）或“should＋动词原形”，意思是“（现在）该……”。
【例】It’s time that I picked up my daughter.
It’s high time we were going.
【例】If only I were a pilot.
If only I had taken his advice.
【例】It would be better for you not to stay up too late.
Would you be kind enough to close the door?
【例】Would you like a cup of tea?
I would rather not tell you.