2. 引導條件狀語從句的連詞

　　1)條件狀語從句主要由if, unless, supposing(suppose)引導：

　　if:

　　I must leave if that’s the case. 如果情況如此我就得走了。

　　He will come if asked. 如果邀請的話他會來的。

　　unless:

　　I won’t write unless he writes first. 我不寫信，除非他先給我寫。

　　I’ll go there tomorrow unless it rains. 除非下雨，否則我明天去那里。

　　supposing:

　　Supposing that he asks you, will you go? 假定他請你去，你會去嗎?

　　Supposing his plan goes wrong, what will you do then?

　　suppose:

　　Suppose she finds out, what shall we do then? 假如她發現了，我們怎么辦?

　　Suppose you lost your job tomorrow, what would you do? 假定你明天失業，你怎么辦?

　　provided:

　　I will agree to go provided(providing) (that) my expenses are paid.

　　如果有人給我掏路費我將同意去。

　　She agreed to go and work there provided that her family could go with her.

　　providing:

　　I’ll dry the dishes, providing that you do the washing-up. 如果你刷盤子，我就將它們擦干。

　　2)條件狀語從句還有其他形式：

　　You will always have a home as long as I have anything.

　　只要我有家產，你就永遠會有一個家。

　　They’ll stand by you even if you don’t succeed. 即使你不成功，他們也會支持你。

　　此外，as long as, so long as, in case, even if 都起連詞作用。