All the words so far

Dada

Mama

"Nigh-nigh" also means binky 

Wawa = water

Up pronounced uppa 

Ditto for Giddo

Sitto for Sitto

Sit

Head

Nose

Eyes

Ears

Baby

More (in sign language and you try to say it)

No

Okay

Hello

Goodbye

You sort of sing "uppaabovethe" from twinkle twinkle

Neigh for a horse

EieiO

You know the sign for hat and dog
Bite = give me a bite
hair
ears

I am probably forgetting one or two more

For everything else there's a grunting mmm sound. 

You understand much much more though. And your certainly try to say and repeat a lot of what we say.