In general, we can slip up in a verbal conversation and get away with it. A colleague may be thinking, “Did she just say ‘irregardless’?”, but the words flow on, and our worst transgressions are carried away and with luck, forgotten.
That’s not the case with written communications. When we commit a grammatical crime in emails, discussion posts, reports, memos, and other professional documents, there’s no going back. We’ve just officially gone on record as being careless or clueless. And here’s the worst thing. It’s not necessary to be an editor or a language whiz or a spelling bee triathlete to spot such mistakes. –Jody Gilbert –10 flagrant grammar mistakes that make you look stupid (Tech Republic)
I’d call these copyediting errors rather than flagrant grammar mistakes, but that’s quibbling.
Of course, I make mistakes, too. (My sister regularly alerts me to typos on this blog.) As an English teacher, I’m very conscious of the way that class makes its mark in our language. I’m personally interested in correct grammar because I not only love the English language but make my living off of teaching about it, so there’s a heavy dose of self-interest surrounding my grammar vigilance.
While I did tell a group of English majors “The world’s hamburgers need to be flipped” when they were frustrated by a lesson on the passive voice, threatening my students that their writing makes them look stupid is not really part of my pedagogical philosophy.