my kid is 21 months old, and doesn't speak any words although he babbles sometimes, shouts and speaks mama, maa , papa, nana that too occasionally.. he responds well to instructions like let's go, sir, shows body parts. is it concerning

A. The speech is less though your child knows a lot so I think you should give it a little more time wait till the age of 2 1/2 years communicate more and more do some rhymes singing with the child child pick up and if you do not getting better by the time of 2.5 then you should definitely see a speech therapist