Semimonthly Madness

Do you ever stop and scratch your head when you have to choose between a term like semimonthly and bimonthly? I do, and for good reason. It’s easy to confuse the prefixes semi and bi.

Here’s one very good reason for the confusion. Take a look at Merriam-Webster’s Collegiate Dictionary definitions of bimonthly: 1: occurring every two months; 2: occurring twice a month: semimonthly.

Excuse me?? How can a word mean both or either occurring every two months and twice a month? Would that mean one month you see the word two times, and then not again until two months later? Sheesh.

For the sake of my sanity, I’m going to pretend I didn’t read that.

Semi means half. Halfway through a period of time would mean you take that time measurement and split it in half. Semimonthly, then, means halfway through the month, or, essentially, twice a month. Semiannually means twice a year. Semicrazy . . . well, that’s me after trying to get a handle on this.

Bi means two, occurring two times. Usually people assume biweekly means occurring twice a week. Or . . . according to the dictionary, it could mean every two weeks.

Here’s what Merriam-Webster’s says about usage: “This ambiguity has been in existence for nearly a century and a half and cannot be eliminated by the dictionary. The chief difficulty is that many users . . . do not bother to make their context clear. So if you need bimonthly or biweekly, you should leave some clues in your context [as to what] you mean.”

I don’t know about you, but now I’m terrified to use those prefixes. But go ahead—use them at your own risk—as biweekly as you like.

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  1. Ah ha! If I’d only had this much clarity about biweekly vs bimonthly back in the day when I was just a lowly marketing manager arguing with the VP on the proper way to address a “twice-monthly” newsletter. Thank you for making the usage perfectly clear.

    I do appreciate your time and the effort you devote to give your readers great information and inspiration to help us on our paths to becoming better writers.

    I purchased your book ‘Shoot Your Novel, Cinematic Techniques To Supercharge Your Writing’. I’m looking forward to learning more details about how to “show” rather than “tell” in my stories, and craft better scenes.

    Thank you for your dedication and for the relevant posts.

    1. I’m glad to add to the confusion … uh, I mean, thanks! Glad you have Shoot Your Novel. It’s a very unique approach to writing scenes and I hope it will help you go “visual” with your novel!

  2. What a fun post! Love it. And yes, I’m terrified to of using those prefixes. Guess I’ll just say, twice a month or every other week. Anyway, thanks.

  3. I actually argued this with my 6th grade teacher 40+ years ago. My reasoning: If semi-weekly means a newspaper every half week, then bi-weekly must mean a newspaper every two weeks. But if she said bi-weekly means two newspapers a week, then semi-weekly means a half newspaper a week?

    I was a foolish child–expecting logical consistency from the English language.

  4. Yet another reason that non-verbal communication is often more reliable than verbal or written…

    Thanks for sharing!

  5. I am so relieved to know that I’m not alone. Bi-weekly – bi-monthly. Ugh. I always have to ask what someone means. I am bi-crazy, but I’m not sure if that is twice as crazy as I thought or only half crazy. I only know now that I am not alone. Thank goodness

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