Grammar is the main skill we teach through Write in Colour - from Kindergarten.
Start small - Just ONE sentence. Learn to create ONE GOOD SENTENCE - at least once a week! This adds up to about 120 good sentences by the end of Year 2. At eight words a sentence - that’s a 1,000 word essay!!!
In early primary school - aim for one very good sentence per day, most days. Quality is much more important than quantity. The process matters far more than the outcome at this stage. They don't need to write a page of writing - they need to focus on quality and constructing very excellent sentences. Offer to write for your child so that they can focus on vocabulary and meaning.
In later primary, many children can construct several excellent sentences or even a coherent paragraph in one sitting when they understand the content. Continue to offer to write for your child so that they can focus on the vocabulary, sentence structure and the process of creating meaning.
Continuing in this was by Year 9 they’ll be able to write a five paragraph essay reasonably independently over a few weeks.
And one day they might head off to University and come home with their first 1,200 word essay saying, "That's easy, isn't it - that's only about six paragraphs!"
It's happened for me - 3 times so far :)