Your coach should be employing the nine (9) point system of instruction that's basic to all "specialty" positions. And although I'm not speaking for other sports/coaches, here's what I do. (regardless, this system is pretty basic stuff)
A pitching coach should:
(2) Observe comprehension
(4) Observe execution
(5) Explain sucess/failure
(6) Observe comprehension
(8) Observe execution
(9) Repeat as necessary.
Now some where along the line, either he or you are missing something. So being fair to all concerned, try to ask your coach to explain in detail exactly what he wants you to do. Then, insure that you understand fully, if not ask for a different approach. *Then ask your coach to demonstrate the best he can, what it is exactly that he wants you to do. Then, try in SLOW TIME exactly what your impression of his instruction was.
COMMUNICATION IS THE KEY HERE. If your not communicating well, you've got to step in and take charge of the situation - not him. Your coach is not a mind reader.
However, let me qualify the above- you've got to have a certain amount of talent going into the train'g process as well as progressing through it. Be fair wilth your estimation of yourself first before appraising your coaches. In short, try not to make the coaching process any more difficult than it already is.
I wish you the very best in your program.
*[/color] With respect to showing you exactly what he wants you to do, please take into account your coach's age. I say this because over the last few years -- I'm up in age and it's sometimes a chore to show exactly what I'm trying to get accross. I even had one smart @#$%@!! say to me once... "Ah coach, you want me to pitch like a 70 year old man??" I could've brained - em!!