German grammar
Seit Vs Vor
Seit means since or for with a continuing situation. Vor means ago in time expressions.
Examples
Ich warte seit Montag.
I have been waiting since Monday.
seit connects past start to now.
Vor zwei Tagen kam Lara.
Lara came two days ago.
vor looks back from now.
Seit gestern lerne ich wieder.
I have been learning again since yesterday.
the action continues.
Common mistake
Mixing since and ago makes German time references unclear.