高校问答lols8怎么赚精粹:for与since的用法与区别
来源：百度文库 编辑：高校问答 时间：2024/04/25 14:18:52
since+过去某一时间或句子,for+一段时间
She has taught in the school for ten years. 她在这所学校教书已经10年了。
I haven't eaten anything since breakfast. 我从早饭起就一直没有吃东西。
只能说一点点 而且很不专业的
for加段时间 表示一个时间段 所以句中的动词也应该是延续性动词 或者类似延续性的 什么时态没区别
since 的用法真的比较复杂 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.
since+时间段，for+时间点···