for与since的用法与区别

Question

如题所述

Answer 1

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。

Answer 2

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.

Answer 3

since+时间段，for+时间点···

Answer 4

for和since
都可用于完成时态。区别：for
后接时间段，如
for
2
years;
since后接时间点，如
since
2
years
ago

Answer 5

1,指时间时，强调延续，for+一段时间，e.g.for
a
year/for
two
days;since
+过去时间或过去时句子，e.g.since
3
days
ago/since
last
week/since
1999.同时与它们连用的句子的动词也要用延续性动词咯，e.g.The
dog
has
been
dead
for
5
days.He
has
had
the
book
since
yesterday.
2，指原因时，for的句子不能放到句首咯。

Answer 6