My son can not talk in regular... When he played or happy then talk not perfect but keep sound

All kids are different..if he is speaking little and even monosyllables or when in mood it's ok for now..many children start speaking properly once they spend some time in preschool..talking to the child is one if the best things you can do..small sentences will do..even ask other family members to speak to him..make story time a routine..also you can make him see rhymes and story videos where characters speak and kids pick up words from there..

Agree with aditi.. Keep motivating. Give him space to answer once you ask a few questions. Read a story book to your toddler and help him repeat few things.