By default, MS Word online is set to automatically detect the proofing language and adjust. The problem is that, if you type something in a non-English language, it does not like to change back to English. I typed in the title of a piece of 15th century music ("À cheval, tout homme à cheval"), and MS did a great job of figuring out that it was in French. The problem was that I couldn't talk it out of using the French rules for checking my English grammar/spelling in the rest of the document. One bit of good news is that the change to French was only for this document, not for everything I write. If this happens to you, here is your way out of the woods: Look in the lower left of your screen. You will see the page count, the word count, and the proofing language. Click the proofing language. A new window titled Language should pop up, with hundreds of language choices. You need to do two things. The obvious one is to choose the language you really want for the re...