英语四级语法辨析要点整理

　　2020年6月英语四级语法用法辨析：since的四种用法，下面小编为备考的同学们整理了用法辨析，希望可以为大家带来帮助，预祝大家高分通过英语四级考试。
　　英语四级语法用法辨析：since的四种用法
　　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)。
　　I have been here since 1989.
　　2) since 一段时间 ago
　　I have been here since five months ago.
　　3) since 从句 Great changes have taken place since you left
　　Considerable time has elapsed since we have been here.

　　4) It is 一段时间 since从句
　　It is two years since I became a postgraduate student.