1 from a particular time in the past until a later time in the past or until now 自从: My parents bought this house in 1975 and we've been living here ever since. 我父母在1975年买了这所房子，我们一直就在这里住。I've been working in a bank ever since I left school. 我中学毕业后一直在银行工作。It was the first time they'd won since 1974. 那次是他们自1974年以来首度获胜。I haven't seen him since last Tuesday. 我从上星期二开始就没有见过他。She has had a number of jobs since leaving university. 她大学毕业后，做过好几份工作。 ☞We use both since and for to talk about how long something has been happening. We use since when we are talking about the beginning of the period of time, and for when we are talking about the length of the period of time I've known her since 1997. I've known her for three years. since和for用以表示某事开始了多久。说事情由某时间开始﹐可用since﹔表达持续的时间则用for﹕I've known her since 1997.我１９９７年以来就认识她。I've known her for three years. 我认识她已有三年。

2 at a time after a particular time in the past 在过去某个时间之后: We were divorced two years ago and she has since married someone else. 我们两年前离婚，后来她和别人结了婚。

3 because; as 因为；既然: Since they've obviously forgotten to phone me, I'll have to phone them. 他们显然忘记打电话给我，我只得打给他们。