Some spelling and grammar errors irk me, and some expressions irk me, but I don't like being corrected, so I don't correct others. I find being corrected on something like that to be petty, disrespectful, and humiliating. And while I don't expect people to not correct others, at least I can decline to do it. The only reason I will suggest a better word or spelling is incase I seriously cannot understand what they said, and the distinction is important. This has happened like 3 times.