since做连词和介词的区别.什么情况下SINCE引导的从句瞬间,和静态动词上表动作的结束,

since引导的瞬间动词作连词。表“自从”e。g。1。She moved to London last May and has since got a job on a newspaper。2。It was the first time I'd won since I'd learnt to play chess。since作介词。放于句首或句中。表“既然”e。g。1。Since the lovely are sleeping,2。Since you come,let's begin!