初二英语语法：条件状语从句

　　连接词主要有 if, unless, as/so long as, on condition that 等初二英语语法。.

　　　　if 引导的条件句有真实条件句跟非实在条件句两种。非切实前提句已在虚构语气中阐述。

　　　 unless = if not.　
Let's go out for a walk unless you are too tired.
If you are not too tied, let's go out for a walk.

　　典型初二英语语法例题
You will be late ___ you leave immediately.　
A. unless　 B. until　 C. if　　D. or
答案A。 句意：除非你即时走，否则你就回迟到的。可转化为 If you dong leave immediately, you will be late.　B、D句意过错，or表转折，句子如为 You leave immediately or you will be late.