例句：

　　I would certainly go if I had time．我如果有时间肯定会去的。

　　If I knew German，I would read the paper to you.我要是懂德语，我就会给你读这篇文章。

　　If he were here，we could ask him．如果他在这里，我们会问他的。

　　If I were you, I would accept his offer.我要是你，就接受他的帮助。

　　If there were no gravity, we should not be able to walk.如果没有地球引力，我们就不能行走。 

　　He would attend the reunion if he weren’t ill today. 他如果没生病，今天会来参加聚会的。

　　It would be nice if it were a holiday tomorrow.如果明天放假，那该多好。

　　If he had any money, he’d leave home.要是他有钱，他就会离家出走。

　　If I knew English, I should be able to read these English books.

　　假如我懂英语，我就应该能读这些英语书了。

　　If you were Mary，what would you tell her? 如果你是玛丽，你会对她说什么？

句型说明：

　　1.在非真实条件句中be不论主语为第几人称，一律用were.

　　If I were a bird, I would fly to you. 假如我是一只鸟，我会飞到你身边。

　　2.主句中除了would之外，还可用情态动词could, might, should.

　　If I were you, I would (could, might, should) help him.

　　如果我是你的话，我就会（可能，或许，应该）帮助他了。

　　She might help if she knew the truth. 如果她知道真相，她也许会帮忙的。

　　If he had much money, he should buy it. 如果他有许多钱, 他就该把它买下来。

　　3. 虚拟条件句也可以位于主句之后。

　　You could meet her if you went to the library this afternoon.

　　你今天下午若去图书馆，你就会遇见她。

　　You could have done better if you had been more careful.

　　要是细心一点的话，你就会做得更好。

　　4. 引导非真实条件从句的连接词，除if之外，以下几种连词引导的从句有时也可用虚拟语气：

　　1) unless  (= if …not)  除非           

　　2) suppose/ supposing ( that) (= if ) 假如

　　3) provided/ providing (that) (= if only)     若….

　　4)  even if  即使

　　5) granting / granted ( that)  (= if 或even if) 即使   

　　6) so long as   只要

　　7) but that(= if not )若不是

　　1) If only I had more money, I could buy a car. 只要我有更多的钱，我就能买一辆车。

　　2) Supposing it were fine tomorrow, would you go swimming with us?

　　假如明天天气好，跟我们一起去游泳好吗？

　　3) Suppose he came, what would you say to him? 假设他来了，你会对他说什么？

　　4) He could not walk unless he had some help. = He could not walk without help.

　　除非他得到一些帮助，否则他无法走路。=不得到一些帮助，他无法走路。

　　5) Even if he were here, he wouldn't be able to help you．即使他在这里也不会帮你。

　　6) Nothing could have saved your father，even if the doctor had arrived on time．

　　即使医生按时抵达，也无法挽救你父亲。