since主句和从句时态

用法

1、Since作为介词，后接某一确定的时间点，主句谓语动词是持续性动词，常与现在完成时态、现在完成进行时态或过去完成时态连用。

例如： He left the village in 1982 and I haven’t seen him since then.

1982年他离开这个村子，从那以后我再没见过他。

2、Since作为副词，表示从过去以来、以后或到现在的情形或状态，常与现在完成时态连用。

例如：He left home two weeks ago and we haven’t heard from him since.

他两周前离开了家，到现在我们一直没有他的消息。

3、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。

4、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。

5、接时间状语从句

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.用现在完成时，而且须是延续性动词；从句的谓v.用一般过去时，而且须是终止性动词。