IRN not chripping

[Amna Hamid]

keeps quite all the time and not chiriping ... whenever i starts a video from youtube of parrot chriping then he seems to be restless and moves in his cage from one corner to an other corner and also make littely sounds like chriping for one or 2 times ... he is 4 or 5 months old but not confirmed ...
please light on this why he is not chriping or seems to b restless every time??