It's best to avoid using and/or, but what should you do if you have to use it?

Mignon Fogarty
1-minute read
Episode #481


Kelly asked whether and/or in a subject makes the verb singular or plural. For example, what verb should she use in a sentence like this:

This message and/or attachments [is? are?] confidential.

You'd be hard pressed to find a style guide that doesn't admonish you to drop and/or and rewrite the sentence with just and or just or.

If you feel you must use and/or, my nonscientific survey of professional writing shows that you probably want to treat and/or as though it makes the subject plural. For example, Kelly's sentence would read

This message and/or attachments are confidential.

Usually, rewriting the sentence with or better reflects the meaning you're trying to accomplish with and/or, but sometimes people try to add clarity by adding or both to the end of the sentence:

This message, or attachments, or both are confidential.

In Kelly's case, a slight rewrite with and is probably the best choice:

This message and any attached files are confidential.

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About the Author

Mignon Fogarty

Mignon Fogarty is the founder of Quick and Dirty Tips and the author of seven books on language, including the New York Times bestseller "Grammar Girl's Quick and Dirty Tips for Better Writing." She is an inductee in the Podcasting Hall of Fame, and the show is a five-time winner of Best Education Podcast in the Podcast Awards. She has appeared as a guest expert on the Oprah Winfrey Show and the Today Show. Her popular LinkedIn Learning courses help people write better to communicate better.