I am deaf myself and when we first got Macy for my birthday. She was 7 weeks old. I started teaching her sign language right away and she got up on it so fast. The signs she knows now are:
Eat
More
Jump
Bark
Sit
Light
Treats
Walk
Outside
Potty
Bed/Sleep
I taught her how to lick my fingers while me doing the I Love You sign.
Do you teach your Yorkies/other dogs sign language if you know any??