Thank you for your quick reply! SuStel:
-choH is used to indicate a change of state occurring. Without -choH (or a verb whose meaning includes the concept of a change), no change of state occurs.
(...)
choQuchmoH I am happy, and it's because of you. choQuchchoHmoH You make me go from unhappy to happy.
I think I understand what you mean. If we want to say that someone teaches somebody else Klingon grammar (as a general fact), we could say: *ghaHvaD tlhIngan Hol pab ghojmoH* But if I want to say that someone couldn't understand the Klingon grammar, but with someone else's help she or he can now understand, we could say: *ghaHvaD tlhIngan Hol pab ghojchoHmoH* However, I still cannot understand this other canon example: *DaH jIbwIj vISay'nISmoH*. Shouldn't it be here *vISay'nISchoHmoH*? I'm afraid I'm not really understanding it yet...