Tracking issue for mistakes assumed to be basic or common but are actually subtle and possibly rare

A thing we all tend to do when testing a grammar checker in our native language is to make up (contrive) sentences with typical mistakes.

But unless we're used to working on grammar checkers, NLP, linguistics, teaching English, etc. we can tend to make incorrect assumptions about what errors are "basic" or "common".

From time to time we get issues filed (or other feedback) embodying this.

This tracking issue aims to gather them all so that we can see patterns, read up on old discussion threads, and be able to find subtle issues when that's what a contributor wants to work on.

No files, tests, or entry points are named. Review existing issue reports and discussion threads about mistakes assumed to be basic or common, then collect them here and summarize recurring patterns so contributors can find subtle cases to investigate.

Written by the indexing model from the issue text.