As PP your little boy seems fab to me, I understood him perfectly and he knows counting too bless him!
My little boy has a development delay in all the areas that the HV's check, he ranges from 10 months to 15 months in his development, he doesn't respond to his name, doesn't talk AT ALL not one single word apart from mamama etc babbling and he doesn't seem to understand anything I really say to him apart from drink? I think he knows what I mean when I say that but nothing else.