I was brought up by my parents to speak the "Queens English" but as soon as I started secondary school I adopted the "native" language spoken there which was semi-cockney. My mother used to despair!! "There is an H in Hat" etc she used to say! but I eventually "got back to speaking normally" but still find that my accent tends to adapt to whoever Im speaking to so when with my partner and mates (East End) I soon drop the H and Ts etc! but can also converse quite well with Barristers, Lawyers etc (when I worked as a legal secretary).
My Son speaks in Chav tounge which I find quite amusing - he is only doing exactly the same as I did. I never chastise him for it because I know he can speak correctly when need be - when he speaks to my parents/anyone he considers important he speaks normally but you should hear him on the phone to his mates - its unintelligible!! usually starts the sentence with the F word which is added in again at 3 word intervals, along with the word Man pronounced "Mun" every few words and plenty of "innit" and most words are "Jamaicanised".
I just try to keep up with the ever changing English language and new words - I often have the odd outburst of "am I bovvered/whatever" just for the fun of it (Im 47 btw!!).
