Word Confusion: Bi- vs Biannual vs Biennial

Posted August 4, 2014 by Kathy Davie in Author Resources, Editing, Self-Editing, Word Confusions, Writing

This one drives me mad. I’m always forgetting which way it goes, so I finally decided to dive into it and figure out what was what. So imagine my surprise when I learned how biwordly the prefix bi- can be. Who knew I could be right twice at a time?

Yep. That’s what I said, and it means you need to be very careful how you word sentences using biweekly, bimonthly, or biyearly as it could go one of two ways. Did you know that a biweekly newsletter could be published 26 times per year…or 104 times a year? Which means that bimonthly publications could come out 6 times or 24 times a year while a biyearly publication could be 2 times a year or every 2 years. Eeek! Makes me think this idea is bifurcated.

Word Confusions…

…started as my way of dealing with a professional frustration with properly spelled words that were out of context in manuscripts I was editing as well as books I was reviewing. It evolved into a sharing of information with y’all. I’m hoping you’ll share with us words that have been a bête noir for you from either end.

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Bi- Biannual Biennial
Credit to: Apple Dictionary.com; Oxford Dictionary: biannual

“20 Ways to Clean with Baking Soda” is courtesy of Networx

I thought two boxes of bicarb was a great way to depict bi-!

“Manhattanhenge” is by Americasroof with this derivative work by David Kernow under CC BY 2.5, CC-BY-SA-3.0, or GFDL licenses, from Wikimedia Commons

A biannual event, the Manhattan Solstice occurs when the setting sun aligns with the east-west streets in Manhattan in New York City.

“Black-Eyed Susan” by Bob Peterson from North Palm Beach, Florida, Planet Earth! is under CC-BY-SA-2.0 license, via Wikimedia Commons

Rudbeckia hirta, the black-eyed Susan, is a biennial.

Part of Grammar:
Prefix Adjective

Also biyearly

Adjective; Noun
Plural: biennials
It’s all about two, whether it’s twice a or every two or lasting for two


[Chemistry] A substance having a double proportion of the radical, group, etc.

[Botany & Zoology; of division and subdivision] Twice over

Twice a year Every two years

Taking place every other year

[Especially of a plant] Living or lasting for two years

A plant that takes two years to grow from seed to fruition and die

An event celebrated or taking place every two years

Rome’s flag is bicolored.

A biathlon combines two sports.

Binoculars are a pair of identical telescopes joined together.

A biweekly newspaper comes out every two weeks or twice a week.

Bimonthly can occur twice a month or every other month.

A biyearly event may take place twice a year or every two years.

A bicentennial is a two-hundredth anniversary.

A biennium consists of a period of two years.

If something is biconcave, it’s concave on both sides.

Bicarbonate is a chemical compound our bodies require for digestion.

Binoxalate is also a chemical compound formed from oxalic acid by the replacement of half the acid hydrogen.

Bipinnate leaves look feathery.

The biannual meeting of the planning committee meets in January and July.

The flight review guide is re-examined biannually.

Summit meetings are normally biennial.

A biennial takes two years to complete its life cycle.

Many biennials will self-seed and appear to be perennials.

The last Whitney Biennial was in 2012 and the next will be in 2014.

The Biennial of the Americas is an international platform for leaders in business, government, civil society, and the arts to examine the significant issues impacting life in the Americas (Biennial of the Americas).

Adjective: bi, biaxial, bicameral, bicarb, bicentenary, bicoastal, bicolor, biconvex biweekly, biyearly, and on and on and on
Adverb: bimonthly biweekly, biyearly
Noun: bialy, bias, biathlon, bifocals, bilevel, bilingual, bilocation, bimonthly, biplane, bistable, biweekly, bi-wiring
Verb: bias
Adverb: biannually Adverb: biennially
History of the Word:
From the Latin, an earlier dui-, related to the Greek di- meaning two and the Sanskirt dvi- meaning doubly or having two. Early 17th century from the Latin biennis from bi- meaning twice + annus meaning year + -al.

C’mon, get it out of your system, bitch, whine, moan…which words are your pet peeves?

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Pinterest Photo Credits:

Spring Flowers” is by AutoGyro at English Wikipedia under the GFDL, CC-BY-SA-3.0 or CC BY-SA 2.5-2.0-1.0 licenses, “Emina Cunmulaj3” by Peter Duhon from New York City, USA, (P9142024.JPG) is under CC BY 2.0 license, and “Bi-colored American Cocker Spaniel and Her Pup” is Galodw13’s own work under CC BY-SA 3.0 or GFDL licenses, all via Wikimedia Commons.