Not a lot. Buster was 18 months last month and I was a little worried as I read that at this age they average about 50 words! But when we saw the MCHN she said it's more like 5 - 10

Mumma
Dadda
Bubba
Peter
See ya
Bye bye
Hello
Cheers
That
Ball, or his version at least
Moo
Ta
Raa
Yep
Book

Think that's it, maybe a few more animal noises.