Memorandum Plural Form: Rule, Examples, and Mistakes
The plural form of memorandum is memoranda (following the Latin plural rule) or memorandums (following the standard English plural rule). Both are correct, but they are used in different contexts. Memoranda is the traditional, formal plural, while memorandums is the modern, informal plural. In business writing, you will see both forms, but understanding when to use each will make your writing sound more polished and appropriate for the situation.
Quick Answer: Memorandum Plural
| Form | Type | When to Use |
|---|---|---|
| Memoranda | Latin plural (traditional) | Formal business documents, legal writing, academic papers, official reports |
| Memorandums | English plural (modern) | Everyday emails, internal notes, casual business conversation, quick updates |
Both are acceptable. Choose memoranda for a more formal, authoritative tone. Choose memorandums for a simpler, more conversational tone.
Understanding the Rule
The word memorandum comes from Latin, where it is a neuter noun ending in -um. In Latin, the plural of such nouns is formed by changing -um to -a. This is the same pattern you see in datum (plural: data), medium (plural: media), and criterion (plural: criteria).
However, English speakers often prefer to add -s or -es to make plurals, because that is the standard English pattern. Over time, many Latin words have developed two acceptable plural forms: the original Latin one and the anglicized one. Memorandum is one of these words.
When to Use Memoranda
Use memoranda in formal writing where you want to show precision and respect for traditional language. This is common in:
- Legal documents and contracts
- Official company policies
- Academic papers and research reports
- Formal internal communications in traditional industries (law, finance, government)
Example: The legal team reviewed all memoranda before the board meeting.
When to Use Memorandums
Use memorandums in everyday business writing where clarity and simplicity matter more than formality. This is common in:
- Internal emails and team updates
- Quick notes between colleagues
- Modern, casual business environments (startups, tech companies, creative agencies)
Example: I sent two memorandums to the team this morning.
Comparison Table: Memoranda vs. Memorandums
| Aspect | Memoranda | Memorandums |
|---|---|---|
| Tone | Formal, traditional, authoritative | Informal, modern, approachable |
| Context | Legal, academic, official documents | Emails, internal notes, casual conversation |
| Frequency in business | Common in law and finance | Common in most other industries |
| Grammar rule | Latin plural (-um to -a) | English plural (add -s) |
| Example sentence | All memoranda must be filed by Friday. | I wrote three memorandums today. |
Natural Examples in Context
Here are examples showing how each plural form works in real business situations.
Formal Context (Memoranda)
- The compliance officer distributed the memoranda to all department heads.
- These memoranda outline the new data protection procedures.
- Please attach all relevant memoranda to your report.
- The board reviewed three memoranda regarding the merger.
Informal Context (Memorandums)
- I just sent a couple of memorandums about the schedule change.
- Can you forward those memorandums to the new hire?
- We usually write quick memorandums instead of long emails.
- She left two memorandums on my desk this morning.
Common Mistakes with Memorandum Plural
Even native speakers make mistakes with this word. Here are the most common errors and how to avoid them.
Mistake 1: Using “Memorandums” in Very Formal Writing
Incorrect: The court received several memorandums from the defense.
Correct: The court received several memoranda from the defense.
Why: Legal and formal writing still prefers the Latin plural. Using memorandums in a legal document can look unprofessional.
Mistake 2: Using “Memoranda” in Casual Emails
Incorrect: Hey team, I attached the memoranda for the project update.
Correct: Hey team, I attached the memorandums for the project update.
Why: In casual internal communication, memorandums sounds more natural and less stiff.
Mistake 3: Writing “Memorandum” as a Plural
Incorrect: Please send me all the memorandum by noon.
Correct: Please send me all the memoranda or memorandums by noon.
Why: Memorandum is singular. You must change the form to show plurality.
Mistake 4: Mixing Both Forms in One Document
Inconsistent: The first memorandum is ready, but the other memorandums are not.
Consistent: The first memorandum is ready, but the other memoranda are not.
Why: Choose one plural form and stick with it throughout a single document for consistency.
Better Alternatives and When to Use Them
Sometimes you may want to avoid the memorandum plural altogether. Here are simpler alternatives that work in many business contexts.
| Alternative | When to Use | Example |
|---|---|---|
| Notes | Casual internal communication | I took notes during the meeting. |
| Memos | Everyday business writing (short for memorandums) | Please read the memos from HR. |
| Documents | General reference to written materials | All documents are in the shared folder. |
| Reports | Formal, detailed information | The reports are due next week. |
| Briefs | Legal or professional summaries | The lawyer prepared several briefs. |
When to use it: If you are writing an email to a colleague, memos or notes is usually better than memoranda. If you are writing a formal legal document, stick with memoranda or use briefs if appropriate.
Mini Practice: Test Your Knowledge
Choose the correct plural form for each sentence. Answers are below.
- The CEO distributed three (memoranda / memorandums) about the new policy to all executives.
- I wrote a few quick (memoranda / memorandums) for my team this morning.
- All (memoranda / memorandums) from the legal department must be signed.
- Can you forward those (memoranda / memorandums) to the marketing team?
Answers
- Memoranda – This is a formal situation involving the CEO and executives.
- Memorandums – This is a casual, quick communication with a team.
- Memoranda – Legal department communication requires formal language.
- Memorandums – This is an informal request between colleagues.
Frequently Asked Questions
Is “memoranda” the only correct plural?
No. Both memoranda and memorandums are correct. Memoranda is the traditional Latin plural, and memorandums is the modern English plural. Your choice depends on the formality of the context.
Can I use “memo” instead of “memorandum”?
Yes. Memo is a common abbreviation for memorandum. Its plural is memos. This is a good choice for everyday business writing because it is shorter and simpler.
What is the singular of “memoranda”?
The singular is memorandum. If you see memoranda used as a singular (for example, “this memoranda”), that is incorrect. Always use memorandum for one item.
Is “memorandums” considered unprofessional?
Not in most contexts. Memorandums is widely accepted in modern business writing. It only looks unprofessional in very formal settings like legal documents or academic papers, where memoranda is still preferred.
Final Tip for Business Writers
When you are unsure which plural to use, consider your audience and the tone of your document. If you are writing to a traditional law firm or a government agency, use memoranda. If you are writing to a startup or a creative team, use memorandums. When in doubt, memorandums is safe for most internal business communication, and memoranda is safe for formal external documents.
For more help with plural forms, visit our Plural Spelling Rules section or check our Common Plural Forms guide. If you have questions, see our FAQ page or contact us.
