My son who is 20 months old does not communicate?


Hi, my son who is 20 months old does not communicate(No pointing etc) however he is potty trained(needs diaper only in night). He knows A-Z, can recognize A-Z and a-z knows 1-20. knows more than 20 animals knows sounds of animals and can tell few colors, knows lots of fruits and vegetables he is very smart otherwise but when it comes to communicate he don’t do anything. if he needs water he keep looking at it and than I have to give it. I’m really tensed if there is any issue with him or its just his nature please advice me what should I do?