Bi-monthly vs. Biweekly – Which is Correct?
The choice between bi-monthly and biweekly hinges on understanding their potentially ambiguous meanings. While both are valid terms, biweekly most commonly refers to something occurring every two weeks, whereas bi-monthly can mean either twice a month or every two months. To ensure clarity, it’s often best to specify the exact frequency.
Bi-monthly or Biweekly – Which is Correct?
Both “bi-monthly” and “biweekly” are grammatically correct words in American English, but their meanings can be confusing due to the prefix “bi-” which can signify “two” or “every two.” The ambiguity inherent in these terms often leads to miscommunication, particularly in professional or financial contexts. Generally, biweekly is understood to mean “every two weeks,” while bi-monthly is the more ambiguous term, capable of meaning “twice a month” or “every two months.”
The Best Trick to Remember the Difference
The best trick to avoid confusion is to remember that “weekly” implies a shorter period than “monthly.” Therefore, if you’re looking for something that happens frequently over a short period, “biweekly” (every two weeks) is likely what you mean. For “bi-monthly,” the potential for confusion is so high that the best trick is to avoid it altogether or always clarify its meaning. Instead of “bi-monthly,” explicitly state “twice a month” or “every two months.”
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| Bi-monthly | Adjective/Adverb | Occurring twice a month OR every two months. | The committee holds bi-monthly meetings (ambiguous: twice a month or every two months). |
| Biweekly | Adjective/Adverb | Occurring every two weeks OR twice a week. (Most commonly: every two weeks). | Employees receive biweekly paychecks (every two weeks). |
How to Use Bi-monthly
The term “bi-monthly” (or “bimonthly”) is used to describe an event or publication that occurs with a specific frequency related to months. However, its use is often discouraged in formal contexts due to its inherent ambiguity. It can mean “twice a month” or “every two months.” For example, a “bi-monthly report” could be issued on the 1st and 15th of each month, or it could be issued in January, March, May, etc. To avoid confusion, it is always best to clarify which meaning is intended, such as “semi-monthly” for twice a month, or “every two months” for the latter meaning. When used, it typically functions as an adjective or an adverb.
Example 1 (Ambiguous): “The club publishes a bi-monthly newsletter.” (Could be 24 issues a year or 6 issues a year.)
Example 2 (Clarified usage): “We have bi-monthly reviews of our project progress, occurring on the 15th and 30th.” (Here, it’s clarified as twice a month.)
Example 3 (Clarified usage): “The journal is issued bi-monthly, in February, April, June, August, October, and December.” (Here, it’s clarified as every two months.)
What are the different forms of Bi-monthly?
“Bi-monthly” primarily functions as an adjective or an adverb. It does not typically have different forms in terms of tense, pluralization, or degrees of comparison, as it describes frequency rather than an action or a countable noun.
Etymology of the word Bi-monthly
The word “bi-monthly” is formed by combining the Latin prefix “bi-” meaning “two” or “twice,” with “monthly,” referring to something happening once a month. The ambiguity arises from “bi-” being interpreted as either “twice within a period” or “every two periods.” This dual interpretation has existed for centuries, leading to ongoing confusion.
How to Use Biweekly
“Biweekly” is generally understood to mean “every two weeks.” This is its most common and accepted usage, especially in contexts like payroll or recurring meetings. For instance, if you receive a “biweekly paycheck,” it means you get paid every two weeks. Less commonly, “biweekly” can also mean “twice a week,” but this usage is rare and often leads to confusion. If you intend to convey “twice a week,” it is clearer to use “semiweekly” or explicitly state “twice a week.” Like “bi-monthly,” “biweekly” functions as an adjective or an adverb.
Example 1 (Most common): “The team holds a biweekly meeting every other Tuesday.”
Example 2 (Payroll): “Many companies offer biweekly pay periods.”
Example 3 (Less common, but possible): “The newspaper published biweekly, on Tuesdays and Fridays.” (Better to say “twice weekly” or “semiweekly” here.)
What are the different forms of Biweekly?
“Biweekly” functions as an adjective or an adverb, describing frequency. It does not have different forms for tense, pluralization, or degrees of comparison.
Etymology of the word Biweekly
The word “biweekly” is derived from the Latin prefix “bi-” meaning “two” or “twice,” combined with “weekly,” meaning once a week. Similar to “bi-monthly,” the “bi-” prefix contributes to a potential for dual interpretation, though “every two weeks” has become the dominant meaning for “biweekly” in modern usage, likely due to its common application in payroll cycles.
Related Concepts
Understanding these related linguistic concepts can help clarify the nuances of “bi-monthly” and “biweekly” and promote clearer communication.
- Prefixes: The prefixes “bi-” and “semi-” are crucial here. “Bi-” can mean “two” or “every two,” while “semi-” almost always means “half” or “partially,” and in terms of frequency, “twice within a period” (e.g., semi-annual means twice a year).
- Ambiguity in Language: This situation highlights how certain words can have multiple interpretations, leading to miscommunication. Recognizing and avoiding ambiguous terms is key to effective writing and speaking.
- Clarity in Communication: The principle of clarity dictates that language should be as unambiguous as possible. When a word like “bi-monthly” has two common meanings, it’s best to rephrase for precision.
Examples from Media and Literature
- “The company’s biweekly report was due every second Friday, detailing sales figures from the previous two weeks.”
- “Her bi-monthly magazine subscription meant she received a new issue six times a year, every other month.”
- “The biweekly paycheck allowed for easier budgeting, as funds arrived consistently every two weeks.”
- “To avoid any confusion, the manager specified that ‘bi-monthly’ meant ‘twice a month’ for the departmental updates, occurring on the 1st and 15th.”
Practice Exercises
Choose the correct word or phrase to complete the sentence.
- The team decided to hold their meetings _______, occurring on the first and third Tuesdays of each month.
- Employees will receive their paychecks _______, meaning every two weeks.
- The newsletter is published _______, appearing in January, March, May, July, September, and November.
- The new schedule requires _______ updates to the project timeline, submitted every two weeks.
- To clarify, the committee meets _______, specifically on the 10th and 25th of each month.
Answer Key
- biweekly (or “twice monthly” / “semi-monthly” for absolute clarity, but biweekly if meaning every two weeks from a fixed start)
- biweekly
- bi-monthly (or “every two months” for absolute clarity)
- biweekly
- bi-monthly (or “twice monthly” / “semi-monthly” for absolute clarity)
Bi-monthly Synonyms
| Synonym | Definition |
|---|---|
| Every two months | Occurring once every two months. |
| Twice a month | Occurring two times within a single month. |
| Semi-monthly | Occurring twice a month (specifically, at two regular intervals within a month). |
Biweekly Synonyms
| Synonym | Definition |
|---|---|
| Every two weeks | Occurring once every fourteen days. |
| Fortnightly | Occurring every two weeks (more common in British English). |
| Semiweekly | Occurring twice a week (less common meaning of biweekly, but a clearer alternative). |
Frequently Asked Questions
Question 1: Is “bimonthly” the same as “bi-monthly”?
Yes, “bimonthly” and “bi-monthly” are generally considered interchangeable and carry the same dual meanings: either twice a month or every two months. The hyphenation is often a matter of style preference.
Question 2: Which term is clearer for “twice a month”?
For “twice a month,” the clearest term is “semi-monthly.” This avoids the ambiguity of “bi-monthly” and explicitly communicates two occurrences within a single month.
Question 3: Should I avoid using “bi-monthly” and “biweekly” entirely?
While “biweekly” is largely understood to mean “every two weeks,” it’s good practice to clarify if there’s any potential for misunderstanding. “Bi-monthly” should be used with extreme caution, or preferably avoided, in favor of explicit phrases like “twice a month” or “every two months” to ensure your message is perfectly clear.
Conclusion
Understanding the distinction, and more importantly, the potential for ambiguity, between “bi-monthly” and “biweekly” is crucial for clear communication. While “biweekly” is widely accepted as meaning “every two weeks,” “bi-monthly” remains a source of confusion, meaning either twice a month or every two months. For precision, especially in professional or financial contexts, always opt for explicit phrasing such as “every two weeks,” “twice a month,” or “every two months.”
Pro Tip: When in doubt, always spell out the exact frequency (e.g., “twice a month” instead of “bi-monthly”) to maintain a professional reputation and prevent misinterpretations.
