Why is homework a fight every single evening?
Because in most households the fight is not actually about homework. A child who argues, delays, needs water, needs the toilet, cannot find the book and then dissolves into tears at 8pm is very rarely a lazy child. They are usually a child who cannot do the work and has no way to say so - because "I don't understand" has, at some point, been met with impatience, and avoidance is safer than saying it plainly.
This matters because the entire standard toolkit most parenting advice reaches for - a fixed routine, a reward chart, removing the tablet, a sterner voice - is designed for a motivation problem. It assumes the child can do the work and is choosing not to. If the actual problem is that your child genuinely cannot do page 43, none of it works, and each failed attempt confirms to everyone in the room that the child is being difficult, when what has actually happened is that a specific, fixable gap has gone unnoticed under a layer of behaviour that looks like defiance.
That is how a two-week difficulty becomes a two-year dynamic. The homework does not get easier on its own, the evening keeps ending badly, and by the time a parent starts searching for "how to get my child to do homework without a fight", the argument has usually been running for months rather than days - which also means the child has had months to build a story about themselves as someone who is bad at this subject, or bad at homework generally, that is at least as hard to undo as the original gap.
So this post starts by separating the two, because the fix for one is close to the opposite of the fix for the other. If you already suspect the work itself is the issue rather than the routine around it, our posts on a child weak in maths and a child weak in reading go into finding the specific broken link, class by class, rather than treating "weak in the subject" as one undifferentiated problem.