since可以作为副词和介词吗？

Question

如题所述

Answer 1

是的，\"since\" 既可以作为副词，也可以作为介词和连词。
作为介词时，\"since\" 后面通常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：I have been here since 1989.(我从 1989 年以来一直在这里。)
作为副词时，\"since\" 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.(他离开家两周了，我们从那以后就没收到他的消息了。)

Answer 2

副词 ad. (常用于现在完成时或过去完成时)

1.此后;从那时到现在
She left school three years ago and has worked as a nurse ever since.
她三年前毕业,从那时起便一直当护士。
2.之前,以前

介词 prep.

1.(常用于现在完成时或过去完成时)自...以来,从...至今
I haven't heard from him since last year.
我自去年以来未曾收到过他的信。

连接词 conj.

1.(常用于现在完成时或过去完成时)自...以来,从...至今
It's been ten years since they married.
他们结婚到现在已经十年了。
She has been living a hard life since her husband died.
她自从丈夫死后,一直过着艰苦的生活。
2.既然;因为,由于
He must have taken the book since it isn't here.
他一定是把书拿走了,因为书已不在这里了。
Since it is so hot, let's go swimming.
既然天气这么热,我们去游泳吧。