OP, DD is almost 22 mos and talking the way you described your son. The pediatrician expressed that she's an "advanced talker" but we're taking that with a grain of salt and think she's average. DD walked at 15 mos and isn't very coordinated compared to other kids her age. It sounds like some kids are better at verbal and others are better at motor skills and the two often don't go hand in hand. Hopefully you're pediatrician can give you some good answers to your questions.