since的用法时态

用法

1）since+过去一个时间点（如具体的年、月、日期、钟点、1980，last month，half past six）。

例如：I have been here since 1989.1989起，我一直在这儿。

2）since+一段时间+ago.

例如：I have been here since five months ago. 我在这儿，已经有五个月了。

3）since+从句。

例如：Great changes have taken place since you left. 你走后，变化可大了。

Great changes have taken place since we were here.我们走后，变化可大了。

4）It is+一段时间+since从句。

例如：It is two years since I became a postgraduate student. 我考上研究生有两年了。

基本字义

since

英[sɪns]美[sɪns]

prep.自从；在…之后；自…后

conj.自从…以来；自从…以后；自…以后；在…之后；因为；既然

adv.从此；此后；后来；之后