i feel your pain, i have put many a post on here about my DD (now 2.11) who wasn't saying more than 10 words when she was 2!! i took her to the GP, the HV assessed her, had her hearing checked, the lot! she just was not talking. i was worried to death, mainly becuase all her little friends were having full on conversations with you and i couldn't even get my DD to say yes or no 
everyone kept telling me she will do it in her own good, she's a late bloomer blah, blah blah, which doesn't help when you are worried sick.
anyway now at 2.11 she is coming out with all sorts, about 3 months ago she just started coming out words left right and centre. Don't get me wrong, we still struggle to understand what she is saying sometimes, and although you can have a conversation with her, it is by no means fluid, it takes a lot of patience and a little bit of prompting at times. i haven' even started counting with her yet as she is still getting to grips with her talking.
what i will say though is her understanding is amazing, and they really do look at this as more important than their spoken words at the moment.
THe advice i was given by the HV was to offer choices, so if she wanted squash i offered her apple or strawberry and waited for her to tell me, if she pointed to what she wanted i would say "apple squash", repeat, repeat repeat so they get used to the words and how they sound. also, getting down to her level helped, and letting her see your lips move helped DD. Also, give him plenty of opportunity to respond to you, leave a good pause for him to say what he wants.
i was so convinced that my DD wasn't a late bloomer and just couldn't speak and that all sorts of help would be needed. i could kick myself now for all that worrying lol
do seek help if you are concerned, a mother's instinct cannot be ignored, and even though GP or HV may try and fob you off (which mine did) do be prepared to push for help, they are not always forthcoming 
HTH