My ds looks more disabled now than he did when he was younger, although he can walk, he uses a sn buggy a lot of the time, often wears big bright yellow ear defenders, and is non verbal, but does a lot of 'chatting' to people ('a a a a' with a lot of accompanying pointing!)
People do ask questions, especially young people,
'can he talk?' ('Not in the way you are used to, but he is very chatty and signs and loves jokes etc')
'Why has he got ear defenders on?' ('Loud sudden noises upset him, and those just take the edge off')
'Why is he is in a buggy?' (Because he gets very tired and sometimes his muscles don't work properly)
I try and be honest, and throw in a positive, and I hope that one day ds will answer for himself. When we are with his sisters, they are amazed that people even bother asking questions, because to them he is just their annoying, loud little brother!
There are also people who are just rude, 'what's wrong with him?' Always strikes me as very impolite. A lady on our road, makes a comment every time we go past and ds is in his buggy, 'oh dear, are you still in that thing, you should be walking now like a big boy, don't you want to run about....' Yadayadayada - these people are just arseholes, and with them I smile and nod and move on.
I started a thread here about having a card that explained very simply ds's difficulties, and not to judge. The thread got mixed responses (to put it mildly!) I did have a card printed up, and keep a couple in the buggy and in my purse, and have used it just a couple of times, where someone was being huffy and rude, and rather than even talk to them I just handed them the card and moved on.