虚拟语气

1. 表示现在/过去/将来情况的虚拟条件句

虚拟条件句主要有三种结构：

1）表示与现在情况相反：主句谓语用“would / could / might +动词原形”，从句谓语用“动词的一般过去时”（动词be的过去式一律用were）。

If I were you， I would not accept his offer.

If I had time， I would certainly go to the cinema with you.

2） 表示与过去情况相反：主句谓语用“would / could / might + have +过去分词”，从句谓语用过去完成时。

If I had got up a little earlier， I wouldn’t have missed the train.

If I had been more careful， I might have passed that exam.

3） 表示与将来情况相反：主句谓语用“would / could / might +动词原形”，从句谓语用“were +动词不定式”或“should +动词原形”。

If I were to do the job， I would not be able to have enough time to study.

If it should rain tomorrow， I would not go out with you.

2. 虚拟条件句连接词if的省略

如果虚拟条件句的从句中含有were， had， should， could等词时，可以省略连接词if，但这时必须把were， had， should， could等词移到主语前面，形成倒装。这种句型主要用于书面形式。

Were I to do the job， I would finish doing it within two weeks.

Had it not been for his help， we couldn’t have arrived there on time.

Should it rain tomorrow， I would stay at home.