Dear friends;
I need your help ,
� You haven �t done your homework yet, so you can �t go out � Sally said to him
Sally told him (that) he hadn �t done his homework yet ,so he couldn �t go out.
I always use this form to change the sentence reported speech. I don �t change yet .
But a friend of mine change YET to BY THEN.
Sally told him (that) he hadn �t done his homework BY THEN,so he couldn �t go out
I don �t remember seeing this usage.
Now my question ;Which one is true ?
COULD YOU HELP ME, PLEASE?
THANKS