After concerns from inspectors that pupils in England were not improving their writing skills quickly enough, the government's standards agency wants to improve children's understanding of grammar.
But since many teachers were themselves never taught the mechanics of English grammar, it has proved necessary first to teach the teachers about the grammatical structures of the language.
The training programme, which will explain grammar to teachers and then show what they should be teaching pupils, will be carried out by teams led by 400 consultants.
The first wave of training will be for teachers of 10 to 11 year olds, with spaces on training courses available for every teacher of this year group in England.
Crafting language
"This will not be an arid approach to grammar," said John Stannard, director of literacy at the National Centre for Literacy and Numeracy, which will be leading the training.
"It won't just be a naming of grammatical parts, but will be a very active, investigative approach to understanding how to improve writing.
"We want to give children a chance to craft language and to have an awareness of the grammatical choices when writing."
At present, Mr Stannard said, children's writing is corrected after they have finished - without any teaching of composition or planning a story. And being able to compose a story depends on a command of grammatical options, he says.
Without confidence in grammar, children are limited in what they can write, he says. While they are improving their reading rapidly, writing is being kept behind by uncertainty over grammar.
A report published last year by the Office for Standards in Education identified concerns over writing in primary schools, with inspectors finding that it was not keeping up with the improvements elsewhere in English lessons.