Thoughts on grammar:
Michael Rosen, Guardian.co.uk, Friday 2 March 2012 11.00 GMT
Sorry, there's no such thing as 'correct grammar'
"Whereas linguists are agreed that language has grammar, what they can't agree on is how to describe it. So, while there is a minimum agreement that language is a system with parts that function in relation to each other, there is no universal agreement on how the parts and the functions should be analysed and described, nor indeed if they should be described as some kind of self-sealed system or whether they should always be described in terms of the users, ie those who "utter" the language, and those who "receive" it (speakers and listeners, writers and readers etc)."
"Many people yearn for correctness and this is expressed in the phrase "standard English". The honourable side to this is that it offers a common means of exchange. However, this leads many people to imagine that because it is called standard, it is run by rules and that these rules are fixed."
"Instead, language is owned and controlled by everybody and what we do with it seems to be governed by various kinds of consent, operating through the social groups of our lives. Social groups in society don't swim about in some kind of harmonious melting pot. We rub against each other from very different and opposing positions, so why we should agree about language use and the means of describing it is beyond me."
"So Gwynne, [author of new grammar book], I suspect will have immense amounts of fun and satisfaction telling people what is "right". People attending his classes will feel immensely pleased that they have been told what's right and will probably spend a good deal of time telling other people they meet or read where and how they are wrong."
I do agree that language is owned by everybody, but not that it is controlled by everybody. Grammar is a way to describe language, but language is simply a means of communication, and always in change. There is a body of learned people who keep studying how people talk, and who decide when new 'correct' language should be added to the list. For instance, the word 'Bush lipping' was added as correct American.
So in effect there are two forces in play, how people talk, and what is by and by added to 'correct' language. But 'correctnes' is a fiction when used for something in constant change, and nobody 'owns' it but the users.