TLDR: 4.5 year old boy, quite bright. Regularly repeats phrases back in a whispered way under his breath. Is this still NT at his age?
My 4.5yo DS is a bright little button. He is sweet and chatty and can maintain a good and varied conversation. He has friends at nursery and doesn't seem to have communication difficulties. He can be shy in front of people he doesn't know and in certain situations cowers away as if trying to hide. This doesn't happen that often.
The main thing that I feel is perhaps worth investigating further is that he repeats phrases we say under his breath pretty regularly. It's like he's processing what we've said but I've read that this can be a sign of autism and that children should grow out of this around 3. So we say something and you can hear him whisper it quietly E.g. I'll say 'I think we'll go to the shop this afternoon' and he will whisper 'shop this afternoon'. Can be with any phrase, he will whisper lines back as I read to him.
He will get embarrassed if we comment on it. It's just become a normal part of him which we find quite endearing.
Other things that might be relevant:
He enjoys numbers and will often ask us maths questions, and ask us things like 'what number is 4 1 3' 'what is 42 add 18?' (He doesn't know the answers)
He also like letters and words and will also ask us what certain letter combinations spell (not necessarily ones that make sense). He can read quite well for a preschooler.
He loves board games (can grasp games for 7+easily) and has recently started showing an interest in chess (I have no idea where this has come from as I have no idea how to play - we're learning together, he keeps beating me!)
He can get overwhelmed in shops and is almost frantic by the end of a supermarket shop. We have to shop online.
With the above written out it looks like quite a few possible signs but overall I'd say most of these things on their own wouldn't concern me and are not a problem day to day, it's the repetition thing which I feel potentially is the thing that might be most unusual at his age. Do some children just take a while to grow out of this stage of language development?
I've written a real essay here. Will summarise at the top 