四六級頻道為備考英語四六級的同學整理了《2019年12月英語四級語法用法辨析：since的四種用法》一文，希望可以為大家?guī)韼椭A祝大家高分通過本次考試!
2019年12月大學英語四級語法用法辨析匯總
英語四級語法用法辨析：since的四種用法
1) since +過去一個時間點 (如具體的年、月、日期、鐘點、1980, last month, half past six)。
I have been here since 1989.
2) since +一段時間+ ago
I have been here since five months ago.
3) since +從句
Great changes have taken place since you left.
Considerable time has elapsed since we have been here.
4) It is +一段時間+ since從句
It is two years since I became a postgraduate student.