when home' the other day... but then most kids in her day care class don't say much at this stage... as long as he's babbling and grunting i don't think you have anything to worry about for now.
as others have said maybe raise it at your 18 month check if worried. but there is such a huge range of normal. if kids are making an effort - babbling, understanding what you say, following instructions - they are probably just taking their own sweet time. believe me, give them 6 months and you will be on here looking for ways to shut them up. but i would also say follow your 