MissStrawberry- please, please don't be too disheartened. The lovely young man I talked about earlier was foul, at times, for many years. I can remember, even now, sitting in the car with him one time and pressing my lips so tight together it hurt, I was so angry with him.
Other times, when he would say he hated me, I would yell back "Well I don't like you very much right now either!" And yes, sometimes, if he offered an apology, I would say "Fine. But I'm not ready to accept it yet. I still need to calm down. You were unspeakably rude."
Term after term after term we were called into school for meetings with teachers/head of year/vice principals because of his behaviour. I used to rant (not in his hearing) that I couldn't wait until he went off to uni, because the thought of living with him after he'd finished school was too awful to bear.
But. Somewhere along the way he started thinking about what he wanted to do/where he wanted to be as an adult. (At the beginning of GCSE years, actually). And he changed. Started doing homework, paying attention in class. And he started becoming nicer at home, too. Now he's nearly 18 and will be off, next year. And I will miss him.
One thing I did notice. Dh (not his bio Dad) would always make a big deal of any infractions, going on and on about them. But when he did something good, it would be a fairly grudging "Well done." So I made sure that I made as much of his achievements as I did telling him off about the bad stuff- balancing out the scales, as it were. Sometimes it was hard to find something good to praise, but when I found it, I made sure he knew all about it.
As much as I may have believed that kids should be good 'Just because', or because I was, or because DH was, I had to realise that some kids just aren't like that. Some of them need a bit more.