一.时间状语从句

引导时间状语从句的从属连词

1.基本类：before、after、when、while、as、since、till、until、once, as soon as, etc. It will be two months before he comes back. It is two years since he smoked.

2. 名词类（由名词词组充当引导词）：the moment ,the minute, the second, the instant,etc. (一…就…); every time, each time, the last time, the first time, etc.

I’ll tell him the minute (that) he gets here. I started the very moment I got your letter.