虚拟语气在if-条件句中的应用

1、英语中条件句分两种–真实条件句和非真实条件句。真实条件句表明假设的情况与实际相符，往往是可以实现的，句中条件状语从句和主句中谓语动词都要用陈述语气。如

If he is your flatterer, he can't be your friend. 凡是阿谀奉承者，不会是你的朋友。

If men have no care for the future, they will soon have sorrow for the present. 人无远虑，必有近忧。

If anyone among the officials breaks the law,he, too should be punished. 长官犯了法，也要受处罚。

2、非真实条件句（即虚拟条件句）表明假设的情况与实际相反或者难以实现，主句说明结果。非真实条件状语从句和主句中的谓语动词都用虚拟语气。其用法主要有：

（1）与目前实际相反的假设：If +subj.+v-ed+(主句) subj.+should/would/could/might+v.

If it were not for hope, the heart would break. 人无希望，心碎肠断。

If we had no winter,the spring would not be so pleasant; If we did not sometimes taste of adversity, prosperity would not be so welcome. 没有冬天，春天不会如此悦人；若不尝一尝不幸，幸运不会如此受欢迎。

（2） 与过去实际相反的假设：If +subj.+had+v-ed+(主句)subj.+should/would/could/might+hve+v-ed.

If she had further considered the problem,she might have come to the correct conclusion.如果她进一步思考过这个问题，她就会得出正确的结论了。

Far more progress would have been made if the importance of the work had been recognized before. 如果早意识到这项工作的重大性，取得的进展就会更快些。

（3）与将来实际相反的假设：If +subject.+should(were to)+v.(有时用subj.+v-ed.)+(主句) subj.+should/would/could/might +v.

If we should miss the train, we should have to wait for an hour at the station. 如果误了这趟火车，我们就得在车站等1个小时。

If it were to rain tomorrow, the match would be postponed.如果明天下雨，比赛就得推迟。

If you missed the film tonight,you would feel sorry for it.如果今晚不去看这场电影，你会感到遗憾的。