在英语语法中，条件句用于表达假设性或不现实的情况，通常使用虚拟语气来传达这些含义。在条件句中，有些句子主句和从句的动作在时间上并不一致，这种情况被称为错综时间条件句。除此之外，英语中还有一些含蓄条件句，虽然不含有明确的条件句结构，但其语气和条件句类似。

　　<例句>

　　If you had taken her advice, you wouldn't be in such trouble now.

　　如果你听了她的劝告，你现在就不会有这种麻烦了。

　　<语法分析>

　　有些条件句主句谓语和从句谓语表示的动作在时间上并不一致，这类句子成为错综时间条件句。还有些句子虽不含条件句，但意思和条件句差不多，这类句子成为含蓄条件句，在这种句子中，也可能需用虚拟语气。某些情态动词在口语里使用得很多，可以使语气变得委婉。

　　<触类旁通>

　　(1) If I had arrived a little earlier, I would have seen her.

　　我要是早来一会就见到她了。

　　语法分析：虚拟条件句，表示纯假想的情况。

　　(2) If it hadn't been for the doctors' care, he wouldn't be speaking to you now.

　　要不是有医生们的照料，他此时不会和你说话的。

　　语法分析：主句谓语和从句谓语表示的动作在时间上不一致，称为错综时间条件句。

　　(3) In the old days he would have argued.

　　要是在过去他早就争论上了。

　　语法分析：有些句子虽不含条件句，但意思和条件句差不多，在这种句子中有时也需用虚拟语气。

　　(4) Would you tell me how to get to the tube?

　　可否告诉我如何去地铁站?

　　语法分析：某些情态动词如should, would, could及might等在口语里使用得很多，可以使语气变得委婉。

　　(5) I might have come to a wrong conclusion.

　　我也许得出了错误的结论。

　　语法分析：这类带有情态动词的句子，其谓语不一定是虚拟语气，但却比较接近虚拟语气。

　　<巩固练习>

　　(1) If I had enough money, I _____ buy a new table.

　　(2) If you tried again, you _____[may] succeed.

　　(3) If she had a permit, she _____[can] get a job.

　　(4) _____[be] I you, I would refuse.

　　(5) _____[be] it not for their loan, our life would be very difficult.

　　(6) If she were leaving, you _____[hear] about it.

　　(7) He _____[do] anything to make amends.

　　(8) Anybody else _____[believe] you.

　　<参考答案>

　　(1) would (2) might (3) could (4) Were (5) Were (6) would have heard (7) would have done (8) would have believed