^
That's a constructive answer Boon Mee.

Buadhai, keep working on it, don't give up.
Koh baht torasap D-TAC
Always fid "Ao DTAC Loi Hasip" does the trick in those situations, though in CM, they may be more used to speaking with jonny foreigner and not close their minds to the possibility of understanding you from the outset.
Koh sounds very stilted to me and I rarely hear it used.

Watch Academy fantasy and Big brother, believe it or not it really helped me.

keep a vocabulary bag, with litle slips of paper, the Thai on one side and the English on the other, take out a slip randomly and translate whichever side comes out into English or thai, this really helps your vocabulary range.