Aiden is 15 months on he 28th and he still really doesn’t try to say anything and I can’t for the…

Aiden is 15 months on he 28th and he still really doesn’t try to say anything and I can’t for the life of me get him to wave! He does learn new things and I’ve never really been concerned before but I see a lot of other kids his age saying more and doing more. Is it normal for his age? I know you’re not supposed to compare but it’s so hard sometimes 😩