since/sɪns/

prep. from a time in the past until now

conj.

➊ from an event in the past until now

➋ used to give a reason or explanation for sth

ad. from a past time until now

prep. [与完成时连用] 从…以来，自…以后：I haven't seen him since Monday. 星期一以来我一直没有看见他。

◇I've been waiting for her since nine o'clock. 9点钟后我一直在等她。

◇since then 自从那时以来

conj.

➊ [常与完成时连用] 从…以来，自…以后：He has had three jobs since he graduated. 他毕业后已经做过3份工作了。

◇[It is ... since +主语+过去时] It's five years since I (last) saw him. 自从上一次见到他以来已经有5年了。

➋ 由于，既然，因为：Since you've finished all your homework, you may go out and play. 既然你已经完成了所有家庭作业，你可以出去玩了。

ad. [与完成时连用] 从那时以来：She moved to Beijing two years ago and has lived there (ever) since. 她两年前去了北京，之后一直住在那儿。

常犯错误

✗ I have been working here since ten years.

✓ I have been working here for ten years. 我在这儿已经工作10年了。

常犯错误

✗ It's five days since he has returned.

✓ It's five days since he returned.

✓ He returned five days ago. 他5天前回来的。

用法一般用“It's + 一段时间 + since ...”，美语中也可用“It's been + 一段时间 + since ...”。

辨析after; since

辨析as; because; for; since

辨析from; since