At 5 he can have the last word but he can't have the final say.

In my experience a young child who's giving out backchat is not convinced your being serious, they don't like being told off and attempt to make light of it so they can avoid mum/dad being cross with them. Have serious conversations under serious conditions...ie sit them on a chair, turn of the tv and other distractions, stop what your doing and then talk. You need to give out the signals that you mean it and then the back chat stops. There not going to take you seriously while your peeling potatoes or driving the car...discuss/debate things under those more relaxed conditions, anything where the message really has to get home needs your full attention.(Tried and tested on 4 of my own and works 99% of the time )

hi thanks for advice an example when you are driving car and hes said something and you need to say no you cannot or we are not going to he will come out with yes i am or we are, answers like that all the time its so frustrating i end up feeling like with him he will not shut up going over my last word any advice on that situation even though he doesnt end up with what he wants its the answering i do not like from him my other child never answered back and took no for an answer alot quicker no roblem with him.demaning nature all the time wears me out.any help

Hi,
One thing I have learned is that all children are different, even within the same family. What works with one doesn't work with another.
It is good your son is not getting his own way, despite his 'back chat'. Try not to get into an argument with him.... (my eldest is an expert at dragging me into an argument and as soon as I allw myself to get dragged into an argument, she's won!!!!))....You could try saying 'You can say what you want, it's not going to change what is happening' or 'It's not ok to speak to me like that. Don't speak to me like that'. Make sure you model good behaviour too...
If the way he is speaking to you doesn't get a major reaction from you, and when he speaks nicely he is praised I'm sure he'll grow out of this phase.