区别since 和for的用法

区别since 和for的用法

for: (prep) 表示时间的持续，后面加时间段，表示一段时间，多与带数词的名词连用，其谓语需用延续性动词。

We have been leaning English for two years.

since: (prep) 表示“自从过去某一时间点以来”，后面接点时间，强调动作或状态一直延续到现在，一般用现在完成时或现在完成进行时。

I have been skating since 9 o’clock.

How long have you been doing that? Since 2 years.

The skating marathon has been going for eight hours.

I have been collecting kites for seven years.

He has been watching English movies since 9 p.m.

I have been listening to music videos since 1999.