My nephew is already two years old, he is very active, he can already climb the stairs, walk and run fast, jump etc. but me and my sister in law are concerned because he can't still talk like most child of his age. Is that normal? What can we do to help him develop his language ability? I also noticed that he can understand simple commands like to put his toys in place, he can also hear what we say because he reacts.

Looking forward for your answers and tips. We really need your help.
Thank you.