since的用法.doc
2页
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. / 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 (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”如 It’s / has been three months since he moved to this city. 要求：主句的谓v.用一般现在时或现在完成时；从句的谓v.用一般过去时，而且须是终止性动词。
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, …(时间)已经过去了”如上个例句还可写成：Three months has passed since he moved to this city. 要求：主句的谓v.用现在完成时，而且动词必须是has passed；从句的谓v.用一般过去时，而且须是终止性动词6)注：当since用于否定句时，主句的谓v.可以是终止性动词如 He hasn’t seen the film since last month.(7)相关词组：“从那时起”：ever since、since then、from then on.注：ever since作为一个词组，放句尾可单独使用如I have given up smoking ever since. 另外，还可在since后接句子since前加ever，只是加重语气而已如 I have given up smoking ever since I caught a bad cough. (8) 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.。
