假設語氣
過去事實相反
現在事實相反
未來
小可
不可
大可
If he/we were rich ,
he could buy a house
If he had $, he would buy a house.
If he had been rich, he could have bought a house.
If he had had $, he would have bought a house.
If he is rich, he will buy a house.
If he eats my cake, I will cry.
If it rains tomorrow, I will not come.
If he should be rich, he can/could buy a house.
If it should rain, I will/would not come.
If he were to be rich, he could buy a house.
If it were to rain tomorrow, I wouldn't go out.
Had he been rich, he....
Had he had money, he .......
Were he rich, he......
Should he be rich, he......
Should it rain, I......
It is (high/ about) time that you went to bed.