I just encounter one question. Today I´ve be asked" have u talked with XX?" and I replied as "not yet". then the man complained my english. So my question is what´s "not yet" exactly mean?
If this was your conversation:
A: "Have you talked with Mr X?"
B: "Not yet."
then your "Not yet" was fine. It meant "I have not yet talked with Mr X".
Not a professional ESL teacher.