[MrDK]

Most members on this board will never be in a position to have an even half ass conversation in Thai, yours truly (maybe) included.
On the other hand many of us know some very basic phrases such as:
Sawasdee khrap (or kha): Hello
khorb koon khrap (or kha): Thank you
Aroy or Aroy Mak: Delicious or very delicious
Mai ben rai: Never mind
Chok dee: Good luck (also used as in cheers)

Question for those who master more than the very basic (or more than has been mentioned here):
Which [new] simple phrase(s) would you teach a person who is on/near bare grounds?