Originally Posted by Mountain Man

"Cha" is what you mouth to indicate that something is very large (as in volume). There are different adverbials used to indicate height ("tah") and distance ("fah"). "Pah" is most commonly used with the sign for SUCCESS and could be interpreted as "Finally!". While it is coupled with other signs, I can't think of them at the moment.

Edit: Ah, man, Reba beat me to the punch! lol