Question

英语中，for和since有什么区别

Answer 1

since可以用作介词或连词，意思为“自从……起”，表示某个动作从某个过去的时间起一直进行，直到说话时间，所以since如果是连词的话，since后面句子一般要用一般过去时，而它的主句则要用现在完成时。如：I have lived here since i first came in 1999.

for可以作为介词或并列连词。作介词表示时间时，表示动作持续的时间跨度，一般用在现在完成时中，如：I have lived here for ten years now.

当然了，for作介词还有其他意思，这里不再赘述。

Answer 2

since可以用作介词或连词，意思为“自从……起”，表示某个动作从某个过去的时间起一直进行，直到说话时间，所以since如果是连词的话，since后面句子一般要用一般过去时，而它的主句则要用现在完成时。如：I have lived here since i first came in 1999.
for可以作为介词或并列连词。作介词表示时间时，表示动作持续的时间跨度，一般用在现在完成时中，如：I have lived here for ten years now.
当然了，for作介词还有其他意思，这里不再赘述。

Answer 3

for+时间段；since+时间点或句子。

He's been in the army for three years.

He's been here since he came.

He's been here since three days ago..

Answer 4

一，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、ago. 1990 , last month , half past six I have been here since 1990. 1990起，我一直在这儿。
2，since+ 一段时间+ago
I have been here since five months ago。自从五个月前，我已经在这儿了。
3，since+从句Great
Changes have taken place since you left. 自从你走后，已经发生了很大的变化。
4，It is +一段时间+since从句
It is two years since I became an English teacher. 我成为英语老师有两年了。
二，Since 和for区别
1，Since +时间点，具体时间
“自从、、、以来，从、、、以后” 用来说明动作起始时间 。
I have been in Beijing since 2010.
2，For + 时间段，用来说明动作延续时间长度，因此句中的谓语动词，也应该是延续性动词。
I have been in Beijing for one year。
We have learnt English for about three years.
I have been here for 3 days. (对)
I have arrived here for 3 days.（误）