My DS 18 months can say: Mum, Daddy, hot, cat, car, all gone, I don't know, Oh god, Oh dear, up there, in there, out there, Jack, Nanna, 1,2,3, tractor, jumper, duck, moo, quack quack, mieouw, yes, no, hat, head, nose, more, cup and I think that's it. It is only really in the last 3 weeks that he has started to talk more.
Really shouldn't compare because he has 2 friends the same age, one talks in sentences, the other says 2 words. Depending on how I feel he's either advanced or behind - this comparing lark only causes brain ache!