Praise your child for trying.
Listen to your child so that when he does try to speak or say a word you can praise him. It does not matter if you don’t understand him completely or if his words are not pronounced ‘properly’. If you think he may have tried to say something, say for example, “yes, it’s a car”.
By praising your child for his attempts at speech he will want to try again and gradually his language will increase and his speech sounds will improve too.