If you do something nice without being paid, you do it “gratis.” Technically, such a deed can also be “gratuitous”; but if you do or say something obnoxious and uncalled for, it’s always “gratuitous,” not “gratis.”
This is the ten-year anniversary of the Common Errors in English Usage calendar. To celebrate, we are bringing back some of our favorite interesting, funny, but sometimes merely silly entries through the years before going on hiatus in 2016.
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