Is it ever worth the time and effort to correct someone else's grating grammatical mistakes? [closed]

There is nothing wrong with having gut reactions to the way that people say things. I am completely aware that the standard/educated version of a language is arbitrary (i.e. is no more "correct" in any real sense than any dialect), and even still, I have pet peeves and things that irk me about people's language usage. I think these are unavoidable, just like my reaction to certain fashion choices that people make in their outfits. But, like with fashion, there is very little objective truth to my judgment about any of it.

I try not to actually challenge people on uses that bother me; aside from the arbitrariness of language, every bit of evidence suggests that stopping language change in any significant way is like going to the beach and trying to stop the tide from coming in. There was a more in-depth discussion about this in a previous question.

That said, I do believe there is a certain time and place where standards and clarity are important. In formal contexts, information is often supposed to be presented in a certain way, and, generally, these conventions benefit everyone. Also, following certain language conventions in these situations can eliminate ambiguity. If I am asked to proofread an academic paper that my colleague has written, I would make corrections for things that I would never object to otherwise.

For me, it depends on the context. In speech, I'd let it pass in anyone except my kids. I would correct them because it's one of my jobs as a parent to teach them a good command of their native tongue.

In casual emails and similar written communications, I'd also let it pass (kids aside); indeed, even in formal emails or documents sent by customers or the like. But in formal documents that I'm reviewing (design specs and the like), then I'll fix the problem, not necessarily with a comment, but often with 'change tracking' enabled.

If it is in part a problem with 'English as a second language', then I'll point it out to the person so that they can improve. That's especially the case if they use the 'please excuse my English' line; they are, of course, completely excused - if only because my command of Spanish, Chinese, or whatever is so much worse than their command of English - but I assume that is an indication that a private answer (not a public one) that improves the 'Use of English' will be of some assistance to them. In a public response, I won't correct them.

So, as I said, it depends a lot on the context. It always grates on me, but quite often there is nothing useful that I can do. When there is something I can do, I'll try the correction. If it causes angst, I won't repeat the exercise with that person. If it is well received, I'll help in future when the occasion arises.