Humour me for a minute. I don't know if DS has PDA, but have been reading around it and the descriptions are absolutely spot on to the particular behaviours we are struggling with at the moment. We've tried all of the usual (over the last three years, not chopping and changing approaches) and nothing is helping, so if this is a new approach we haven't tried I'll give it a go. DH has already said if we don't see an improvement in a year's time after he starts school (we are in Germany, he's 6, not 4.)
He is a lovely child until you ask him to do something perfectly innocuous and then the ridiculousness starts. I find it very, very difficult to manage because it's so frustrating - he's not resisting, he's avoiding. Just like the description. The EXACT same things as those websites say. "My legs hurt." "My hands are made of lava" "What day is it today?", long long spiels of conversation which he won't break for anything to avoid the fact that he's supposed to be listening to you. Arguing, crying, fighting, silliness over the same things that he has to do regularly, even has a chart to help him count down to, has to do EVERY day, it's not a surprise, as soon as he finally gets in there he's singing away perfectly happy, it's just the fact of being told "It's time for your shower now".
So all of the websites say that to help them you're supposed to pick your battles (okay, we already do, but he has to get to kindergarten, and go to bed, and shower/bathe, and brush his teeth and we like him to help out around the house and get off the playstation when he's asked to.)
Change the way you ask. Most of this is stuff I had picked up years ago that seems to work better for him. (Even as a toddler, asking "Can I hold your hand?" was 100x more successful than "Hold my hand"). Demanding/barking orders never works. Letting him do things at his own pace, maybe. Changing the way you word it, the most successful, but sometimes things need to be done, and now, not in an hour after you've finished sighing and flopping.
But still - I lose patience with it. Once I've said something "wrong" it's just started off a chain reaction - he will expend easily ten or twenty times as much energy and time avoiding or arguing against something than he would have done just doing it. Sometimes extreme anxiety or anger, sometimes giggling and running around and playing games and pretending he's deaf or injured or whatever. And I worry about these ways of managing it - is it really helpful to pander to it when he will one day be an adult, underneath people other than us and have to do things that other people say sometimes? If he learns it's an okay way to be, how will he ever hold down a job? I realise I'm catastrophising a bit, and I absolutely don't believe children should be little army sergeants obeying every order immediately, in fact I'm quite against this idea, but it's difficult to live with him when he takes such umbrage at being asked to do anything at all.
I'm going out so will be back later, but any thoughts at all, I'd be interested.