Question

for 和 since 之间应该如何进行互换?

Answer 1

since后接时间点,for后接时间段.且since一般用于完成时.

eg:I have worked here for 3 years.

I have worked here for 3 years ago.

I have worked here since 2005.

顺便提醒,since..ago这种说法虽不为错,但恐怕除了做题没人会在日常用语中这样说（我们外教说的..）.