My son turns 2 next week and I am wondering the same thing.
I have been told when they know when they go wees and poos.
As soon as my son gets into the bath we does wees or if not then when he gets out and into his bedroom I might put the potty in his room and see if he will go in it insted on the carpet.
He also tells us when he is doing poos (not that it is half obvious)
He also watches his dad and me go to the toliet. Not all the time, (I need some privacy.)
I have been told to be careful as if you rush them and they are not ready then it can push them back further.
Any advice would be great
Tineka, Mum to Hamish 3yrs, Abby 1yr & 1due 10/04