FOR AND SINCE WAHT A SHAME ?

[Guest]

IN PRESENT PERFECT
when wrote I have studyed english since friday OR wrote I have studyed english for friday ........
I think if I write since I must to write last friday but I wrote I have studyed english for friday
but my teacher says that's wrong .
I believe grammar book or my teacher

[Dixie]

I have been studying English since Friday. :R:

Although if you've just started learning the English language it would be also right to say I have studied English since Friday :R: , if Friday was when you first picked up a book on English without any prior teaching

[Guest]

thank you dixie

[Dixie]

Anytime

[sweethuman]

Since is used with exact point of time, Since friday, since 2010, since 8:00 Oclock
For is used for the duration of the time, For 10 hours, for 10 days, for 10 years