Disable grammar checker?

Has anyone found a way to disable the grammar checker yet? I saw something that suggested disabling spell check would do it but it didn't help. The only time I ever interact with it is when it is wrong, which is every time it changes a word. I've never seen it change a word that actually needed to be changed but it does things like change them to the all the time.

I don't mind the other writing tools, I can simply choose to not use them, but the grammar check is actively in the way and needs to go away until it works. I actually like the idea, I just can't use it as it is.

This is about macOS but not specific to it. I want to disable grammar check on my iPhone and iPad too.