Steps in taking power away from us as speakers and writers:
1 Invent an elaborate set of terms about language which you claim are watertight descriptions of, and terms for what these words do.
2. Keep changing these descriptions and terms as you claim that now you've got a better description or term.
3. As you claim you're explaining these terms, use expressions like 'Adverbs modify verbs'. This is in fact complete nonsense because 'adverbs' don't do anything. That's just a description or term that someone has invented. In fact 'language' doesn't do anything. We do it. Whenever we use expressions like 'adverbs modify verbs' we turn a concept into a thing, give it mystical power of being able to act on its own without humans involved. This has the advantage for the people using such expressions that it's as if they or we too possess this magical power in the world and if you are a child or someone who doesn't understand the description or term, you are less capable.
4. The only descriptions and terms for language that actually have sense are those that at least make some nod towards meaning and purpose. When you look down the terms in, say, the DfE's glossary you see that the terms used aren't all of the same kind. It's a ragbag of terms using different methods of description. So, if I describe something as a 'determiner', this is nonsense talk. No word 'determines' another except in the world of giving descriptions mystical powers. If I call a word a 'possessive' though, at least it indicates some degree of meaning and purpose. When I say, 'Give me my hat back' and I call 'my' a 'possessive' at least it gives a bit of a sense that the reason why we have a word like 'my' is because I or you want to express a sense that this 'hat' is 'mine' in real life or in the fictional world I am creating. Not so bad.
5. The present way of describing language through these terms then leads to the totally false notion that when people use them they will be 'right' or 'wrong'. It's false because again and again, we find that the people who come up with the descriptions and terms can't decide on which one is 'right'! Of course they can't, because it's a mystical system. The word 'after' in 'I met him after the match.' and 'I met him after the match was over.' - is according to some 'different' in these two examples, but according to others is the 'same' in these two examples. They take chunks out of each other in arguing over it. This doesn't stop the DfE setting children tests in it, for which there is only one right answer.
6.Even dafter and even more pernicious is the myth that learning this kind of nonsensical stuff will help children write better. All that is happening is that children are being helped to write according to various formulae like 'She used an 'embedded relative clause'. He used a 'fronted adverbial'. She used an 'expanded noun phrase'. To be clear, this has absolutely nothing to do with 'good writing'. It is writing by numbers and not writing for meaning and purpose.
7. I know I keep saying it, but let's remember that the only reason why it came in is because the government wanted a 'reliable' means of testing schools and 'writing'. So they invented a test which they said would have 'right and wrong' answers. (See Bew Report, 2011). It was not brought in on the basis of any kind of intellectual argument in favour of this kind of grammar or on the basis of that this kind of grammar does lead to 'good writing'.
8. Yet again, the powers that control education have succeeded in coming up with tests, theories, practice, and implied teaching methods which take power away from classroom teachers and away from children's control over their own language. Whether they do this knowingly or not is beside the point. It's the consequence that matters.
9. What is the alternative? At primary school level, the best way to talk about language is to look at examples of language in use - whether that's in the writing that we come across, or in the talk we come across. This immediately connects language with how it's used and why. If we want children to write well - in whatever genre or mode - the best way to to do it is get them to compare, contrast different bits of writing, to imitate, adapt it, invent new ways for their own purposes and to discuss what they've written. It's often a good idea for teacher to write at the same time. It's always a good idea to find ways of publishing and performing what they write - blogs, school bulletins, magazines, posters, booklets, wall-displays at the height the children can read...and so on.