Is it ever not considered rude to correct someone's grammar and spelling? Not in a business setting or anything, but will I come off as a dick for pointing out mistakes in an an e-mail, chat, or Facebook comment? Some of my friends type like fifth graders, and it's highly annoying.
I can think of very few situations where correcting someone's grammar would ever go over well. Those situations include: It is your child/student you are correcting, a co-worker with whom you are working on a presentation, or if you are actually discussing grammar when someone makes a grammar faux pas. Then you may chastise him/her, a right guaranteed by several constitutional amendments, I'm pretty sure.