My son is 16 months, but he can only produce two sounds "da" & "ga". We tried to ask him to say more words and he will try very hard but still ends up producing "da" / "ga".
I am not really worried about his speech development at the moment as I know some babies, especially boys, are usually a bit late in mastering speaking skills. I have four mami friends who have boys and all their boys only started speaking at or even after 2. I think, if your kid doesn't speak some simple word at / after 2, you should show some concern. Before that age, take it easy I would say. And I am told that as long as your kid understands everything you say, it shouldn't be a big worry.
My son is constantly 'talked' to every day, by my mum & dad (who look after him when I am at work). At night when I take him home, I 'bombard' him with talking until the moment he falls into sleep. So I think, he has enough "talks" every day but he can still only say "da" & "ga" :))