引导条件状语从句的连词(重点)：

　　1）条件状语从句主要由if, unless, supposing(suppose)引导：

　　if:       If it rains tomorrow , we will have to stay at home.

　　unless:   I won't write unless he writes first.  我不写信，除非他先给我写。

　　2）条件状语从句还有其他形式：(难点)

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

　　只要我有家产，你就永远会有一个家。