Our class 4 son writes three-word answers and his teacher wants full sentences
He reads well above his level and talks endlessly, but on paper every answer is the shortest possible version. 'Why do plants need sunlight?' 'To make food.' Correct, and marked down, because the teacher wants a full sentence that repeats the question. I can see two ways forward. A little practice at home, which he resents because in his view the answer has already been given. Or the English writing class near us that a few parents have mentioned, which would solve it with somebody else's patience but adds another evening out. I'm not sure which is better at this age, or whether it simply sorts itself out once marks start to matter to him.