Hurry up and talk already

A friend and her son have been hanging out with Ari and I lately and I'm incredibly jealous of the little conversations they can have.
Ari can only say a few words - like Mama, Dadda, Nanna - which means that for nigh on 2 years now, I've spent most of my days talking to someone who doesn't talk back.
I can't BEGIN to tell you how frustrating that can be.
I know some of you will be reading this saying "enjoy it while you can because once they start talking, they never shut up", or something to that effect.
Well, I can hardly wait for the day when I'll say something to my son and he'll answer back.
As my dad said only today..."he crawled when he was ready, he walked when he was ready, he'll talk when he's ready". He's right, of course.