Repeatation. What should i do?

My son keeps repeating specific rhymes, words and 2-3 word sentences. Doesn't understand all commands and questions. He shuts/ opens the door when asked to do so. He keeps things where we ask him to keep. He doesn't frame sentences on his own to answer but when we say something to him he remembers that and next time he replies the same. But when we ask what will u eat? Wat do u want? What happened? Etc then he repeats the same questions. Though he tells whenever he needs to pee or drink water or go to loo. Whenever he gets hurt, he says oops " chot lag Gaya... It's ok theek ho Jayega(I said that when he got hurt earlier) as he remembers the same. Then he starts saying finger ko chot lag gya, mumma ko chot lag gya etc. One more thing I would like to share that he keeps watching rhymes on YouTube. Can that be the reason for repeatation? For last 3 days he has not seen any video, although he asks for that but I am trying to get rid of it. What should I do? Thanks in advance