引導(dǎo)條件狀語從句的從屬連詞有if, unless (=if…not如果不……，除非), as/so long as(只要), while(=as long as只要), supposing (that)/provided /providing (that)(假如), in case(假使), on condition that(在……的條件下)等。如：

You can learn anything so long as you set your mind to learn it. 用心學(xué)本領(lǐng)，總能學(xué)到手。

I will go there tomorrow unless it rains.(=…if it doesn’t rain)除非下雨，否則我明天要去那兒。

He will do the work providing you pay him. 如果你能付費，他可以做這工作。

In case l forget，please remind me about it. 如果我忘了，請?zhí)嵝盐摇?/p>

We’ll let you use the room on condition that you keep it clean and tidy. 我們可以讓你使用這個房間，條件是你把它保持整潔。

注：條件狀語從句和時間狀語從句一樣，從句的謂語動詞不能用一般將來時態(tài)、過去將來時態(tài)或?qū)硗瓿蓵r，而要用相應(yīng)的一般現(xiàn)在時、一般過去時和現(xiàn)在完成時態(tài)來替代。又如：

Tell me in case you get into difficulty. 遇到困難請告訴我。

Supposing he does not come, shall we go without him? 如果他不來，是不是不帶他去?

但若從句謂語用了will或would，那will或would則是表示“愿意”的情態(tài)動詞。如：

If you will go with me, I’ll wait for you. 如果你愿意等我，我們就幫你做這事兒。