It is a Best Practice to check the spelling, syntax, and sanity of your documentation. I agree with this, strongly.
I wish it weren’t necessary to point this out, but it really is. There are a lot of people (engineers and otherwise) who don’t think that proofreading, spelling, and grammar matter. It does. Not only is your work harder to read if you don’t take care of these things, it looks simply slovenly and as if you don’t care at all about it. If you don’t care about your words, why would I assume you care about the rest of your work?
I do see a difference between an engineer who misspells a word and then has a single variable name, or even type of misspelling, and one who’s just sloppy. I want either of them to fix it, but I understand that spelling can have all sorts of challenges.
I’ve worked with a lot of brilliant engineers who didn’t speak English as their native language. They have to work harder to communicate, and I respect them for that. In addition, the good engineers I’ve known all want to improve themselves and their language, so if there’s something they’ve done that’s wrong, they want to correct it. Gently inform them a better phrasing, and the good ones will be thrilled to learn it, often asking you many questions about why that is. There is a difference between mistranslations or using structure that isn’t quite idiomatic and simply being lazy or sloppy in writing.
Don’t be a lazy writer. It shows.