If it should rain tomorrow we sould not go climbing.

→Should it rain tomorros iwe would not go climbing.如果明天下雨的话，我们就不能登山去了。

⒌ 用介词代替条件状语从句

常用的介词有with,without，but for。

如：What would you do with a million dollars?(=if you had a nillion dollars)如果你有100万元，你会做什么？

We couldn't have finished the work ahead of time without your help(=if we hadn't got your help)没有你的帮助，我们不可能提前完成这项工作。

Without your help we couldn't have finished the work ahead of time.

=But for your help,...

=If it had not been for your help,...

=Had it not been for you help,...

没有你的帮助，我们不可能提前完成这项工作。

⒍ 含蓄条件句

有时在虚拟语气中并不总是出现if引导的条件句，而是通过其他手段来代替条件句。

如：I was ill that day.Otherwise, would have taken part in the sports meeting.(副词）

He telephoned to inform me of your birthday,or I would have known nothing about it.(连词）

A man who stopped drinking water would be dead in about seven days.(定语从句）

I might hawe given you nore help,but I was too busy.(连词）

Everything taken into consideration they would have rai sed their output quickly.(独立主格结构)