1.连接时间点：如 I have stayed in that country since 1995年要求：谓v.使用当前完成时，且必须是连续动词.

2.接一段时间 ago：如 They have lived in that house since two years ago.要求：谓v.使用当前完成时，且必须是连续动词.

3.接时状语从句：如 I have loved her since I met her last time./ Lily has stayed at home since she left school.要求：主句的谓v.使用现在完成时，并且必须是连续性动词；从句所谓的V.一般过去使用，必须是停止性动词.

4.用于句型“It’s / It has been 一段时间 since 在时间状语从句中，翻译为“自打…到目前为止，已经…(时间)”.如 It’s / has been three months since he moved to this city.要求：主句的谓v.使用一般现在或现在完成时；从句的谓V.一般过去使用，必须是停止性动词.

5.用于句型“一段时间” has passed since 在时间状语从句中，翻译为“自打…到目前为止，…(时间)已经过去了”.以上例句也可以写：Three months has passed since he moved to this city.要求：主句的谓v.用现在完成的时候，动词一定要has passed；从句的谓v.一般过去使用，必须是停止性动词.

6.当since用于否定句时，主句的谓vv.可以是停止性动词，比如 He hasn’t seen the film since last month.

7.短语：“从那以后”：ever since、since then、from then on.注：ever 作为短语，since可以单独使用放句尾。I have given up smoking ever since.此外，还可以在since后接语句.前加eversince，只是加剧语气。比如 I have given up smoking ever since I caught a bad cough.

8.Since还可以引导原因状语从句，翻译成“因为”；因为，相当于because.如 Since he was lazy,he didn’t finish his homework.