(非真实条件)如果我是你，我会邀请他参加聚会。

　　3．状语从句的省略

　　在时间、条件、让步等状语从句中，当从句主语与主句主语一致或从句主语是it，从句的谓语部分含有be动词时，可以将从句中的主语与be动词一起省略。

　　He won't go there unless (he is) invited.

　　他不会去那儿，除非得到邀请。

　　I'll come early if (it is) possible.

　　如果可能的话，我会早点儿来。

　　4．祈使句＋and/or＋陈述句

　　"祈使句＋and/or/or else/otherwise＋陈述句"句型中，祈使句在意义上实际上相当于条件状语从句。

　　Give me all your money, and I'll let you go.

　　＝If you give me all your money, I will let you go.

　　给我你所有的钱，我就放你走。

　　5．only if引导的从句置于主句之前时，主句要用倒装语序

　　Only if you carry out the experiment under the desired conditions can you get the best result.

　　只有你在需要的条件下做实验才能得到最好的结果。

　　集中演练1

　　1－1.句型转换

　　①You will fail to arrive there in time unless you start earlier.

　　→You will fail to arrive there in time if you don't start earlier.

　　②In case of rain, we'd better take an umbrella.

　　→In case it rains, we'd better take an umbrella.

　　③If you try some of this juice, you'll like it.

　　→Try some of this juice and you'll like it.

　　④He won't say sorry unless he is forced to.

　　He won't say sorry unless forced to.

　　⑤If you fail, what should you do?

　　→Suppose/Supposing you fail, what should you do?

　　1－2.完成句子

　　⑥如果你今晚有空，我要去看你。

　　If you are free this evening, I shall go to see you.

　　⑦如果我是一只鸟，我将在天空中自由的飞翔。

　　If I were a bird, I would fly freely in the sky.

　　⑧如果有必要的话，多带点钱。

　　Please bring more money if necessary.

　　⑨你只有知道这一切，才能得出结论。

　　Only if you know all about it can you draw a conclusion.

　　⑩只要你答应来，我就等你来。

　　As/So long as you promise to come, I'll wait for you until you come.

语法点二 让步状语从句 　　

　　让步状语从句通常由下列词或短语引导：though, although, even though, even if, as, while, whether ...or (not) ..., 疑问词­ever, no matter ＋疑问词等。

　　1．though, although和as

　　(1)though与although几乎完全相同， though比although通俗，不如although正式，两者通常互换使用。though/although引导让步状语从句时，主句可用yet, nevertheless或still引导，更加强调对比性，但不可用but。

Although/Though he is young, (yet) he knows what is the right thing to do.