DD has just turned 3 and we've been working on this for a while.

She's given simple instructions - could you please put your bowl on the bench, could you put your pencils away, food wrappers into the bin etc.

I get her to help me tidy up the lounge room and her bedroom before the TV is allowed on. She won DH over a while back - she's only allowed to watch TV from 4pm and it was far earlier. She cleaned all of her toys up and put everything away without being asked and then asked him if she could watch TV That made me realise that she is more than capable of understanding what we're asking of her.