since的用法：译作“自从…以来”

(1)接时间点：如 I have stayed in that country since 1995. 要求：谓v.用现在完成时,而且须是延续性动词.

(2)接一段时间 + ago：

如 They have lived in that house since two years ago. 要求：谓v.用现在完成时,而且须是延续性动词.

(3)接时间状语从句：如 I have loved her since I met her last time.

(4)用于句型“It’s / It has been + 一段时间 + since + 时间状语从句”中,译作“自从…以来, 已经…(时间)了”.

(5)用于句型“一段时间 + has passed since + 时间状语从句”中,译作“自从…以来, …

(6)相关词组：“从那时起”：ever since、since then、from then on.

(7) since还可引导原因状语从句,译作“由于；因为”,相当于because.

如 Since he was lazy, he didn’t finish his homework.