I havent read the other posts, but in my opinion the terrible 2's become the terrible 3's and then the terrible 4's!! The main difference being that they become more verbal when they throw tantrums and whinge/ pester a lot. Sorry!

I went to a seminar called "1, 2, 3 MAGIC" and it really helped me. It was run by 'Relationships AUstralia'. I recommend it highly