I nanny a 4 year old and a 1 year old and the 4 year old refuses to be independent on things that he should definitely learn and know how to do

For example: I get him dressed in the morning and he complains that he doesn’t know how to put on his underwear, shirt, pants, socks etc.

And I don’t mean he doesn’t know how as in he doesn’t know it’s facing backwards or not or something like that.. I mean he literally stands there and won’t put it on or even try because he wants you to do it

He 100% knows how to do these things but swears he doesn’t

I picked him up from preschool today and told him to get his jacket on and he grabbed his jacket and then said he doesn’t know how to put it on (he does) and just stood there... I had my hands full holding his backpack and his 1 year old brother so I tied to help the best I could but then his teacher rushed over and yelled at him to listen and put his coat on and then she ended up having to stick his arm in for him because he kept insisting he doesn’t know how

And he’s like this with EVERYTHING... like I’ll tell him when he needs to go potty because he hasn’t in a while and he will insist he doesn’t know how to pull his pants down... and then I literally have to do it for him or else he pees/poops in his pants

I’ve talked to the parents and they said they are going to try to work on that with him but is there anything I can do to help while I’m there????

I mean I understand having trouble getting your shoes on and not being able to tie them.... but pretending and insisting that you don’t know how to dress yourself when you have before or put your coat on when you have before is ridiculous