He also tends to jump repeatedly, or flicks his fingers. Are these things classed as stimming?? He also has verbal outburts of jibberish or just loud sounds, esp if your asking him to do something like say "Pick up your lego Rip" "Put your clothes on Rip". The jibberish talk has increased alot lately, even though we know he has a good vocab even with the speech issues.
Yep, that's stimming. It's another way of saying a repeated physical behaviour. They'll usually use it in a situation when they're in a hightened emotional state (over-excited, anxious) or when they need more sensory input to process something. It helps them calm and organise themselves, but it is an indicator that something is up that you might have to look into.