Quick Answer

Memorandum (singular) → Memorandums or Memoranda (plural). Use memorandums for most business emails, internal notes, and everyday conversation. Use memoranda for formal documents, legal contexts, or when you want to sound more traditional or precise.

Understanding the Two Plurals

The word memorandum comes from Latin, where it is a neuter noun. In Latin, the plural of neuter nouns ending in -um is -a. That is why memoranda exists. However, English speakers have long adopted the word and often apply the regular English plural rule (adding -s or -es), giving us memorandums. Both are acceptable, but knowing when to use each can make your writing sound more natural and appropriate.

Memorandums: The Everyday Choice

In most business environments, memorandums is the standard plural. It is simple, clear, and matches how most people speak. If you are writing an internal email, a quick note to a team, or a casual update, memorandums is the better choice. It avoids sounding overly formal or stiff.

• Example: “Please send all memorandums to the HR department by Friday.”
• Example: “I have three memorandums to review before the meeting.”

Memoranda: The Formal Option

Memoranda is the traditional Latin plural and is still widely used in legal writing, academic papers, and formal corporate communications. If you are working in a law firm, a government agency, or a university, you might see memoranda more often. It carries a tone of precision and tradition.

• Example: “The court reviewed several memoranda of law before issuing its decision.”
• Example: “All memoranda must be filed with the clerk by noon.”

Comparison Table: Memorandums vs. Memoranda

Natural Examples in Context

Seeing the word used in real situations helps you understand the nuance. Here are examples in different settings:

Business Email (Informal)

“Hi everyone, please find attached the memorandums from last week’s meeting. Let me know if you have questions.”
→ Here, memorandums sounds natural and friendly.

Legal Document (Formal)

“The parties submitted their respective memoranda of law on the motion for summary judgment.”
→ In this context, memoranda is the expected form.

Conversation Between Colleagues

“I have to read through all these memorandums before the deadline. It’s a lot of paperwork.”
→ Using memorandums here keeps the tone conversational.

Academic Paper

“The researcher analyzed several internal memoranda from the company archives.”
→ Memoranda fits the formal, scholarly tone.

Common Mistakes to Avoid

Even experienced writers sometimes make errors with this word. Here are the most frequent mistakes and how to fix them:

Mistake 1: Using “Memorandums” in Very Formal Legal Writing

While memorandums is correct, some legal professionals consider it less precise. If you are writing a legal brief or a formal contract, check the style guide of your organization. Many law firms prefer memoranda.

Fix: When in doubt, match the tone of the document. If the document uses memoranda, follow that pattern.

Mistake 2: Using “Memoranda” as a Singular

This is a common error. Memoranda is plural, so you should never say “a memoranda” or “this memoranda.” The singular is always memorandum.

Incorrect: “I found a memoranda on my desk.”
Correct: “I found a memorandum on my desk.”

Mistake 3: Overusing “Memoranda” in Casual Settings

Using memoranda in an informal email can sound pretentious or out of place. Stick with memorandums for everyday communication.

Incorrect: “Can you send me those memoranda from yesterday?” (in a casual chat)
Correct: “Can you send me those memorandums from yesterday?”

Better Alternatives and When to Use Them

Sometimes, you might want to avoid the confusion altogether. Here are alternatives that work in many contexts:

• Memos: This is the most common and practical alternative. It is short, clear, and works in almost any situation. Use it in emails, conversations, and internal notes.
  Example: “I have three memos to read before the meeting.”
• Notes: For very informal contexts, notes can replace memorandums.
  Example: “She left a few notes on my desk.”
• Official communications: In formal writing, you can use this phrase to avoid the plural issue entirely.
  Example: “All official communications must be approved by the manager.”

When to use it: If you are unsure whether your audience expects memorandums or memoranda, memos is a safe, neutral choice that works in both formal and informal settings.

Mini Practice: Test Your Understanding

Try these four questions to check your knowledge. Answers are below.

Question 1

Which sentence is correct for a formal legal document?
a) The lawyer submitted several memorandums to the court.
b) The lawyer submitted several memoranda to the court.

Question 2

Fill in the blank: “I need to review all the ______ from this quarter.” (Choose the best option for a casual email)
a) memoranda
b) memorandums
c) memorandums or memoranda

Question 3

True or False: “Memoranda” can be used as a singular noun.

Question 4

Which alternative is safest for both formal and informal writing?
a) memorandums
b) memoranda
c) memos

Answers

Answer 1: b) The lawyer submitted several memoranda to the court. (Formal legal context prefers the Latin plural.)
Answer 2: b) memorandums (For a casual email, memorandums sounds natural.)
Answer 3: False. Memoranda is always plural. The singular is memorandum.
Answer 4: c) memos (It is short, clear, and works in almost any context.)

Frequently Asked Questions

1. Is “memorandums” grammatically incorrect?

No, memorandums is perfectly correct. It follows the standard English rule for forming plurals by adding -s. Many dictionaries list it as the first or second plural form. It is widely used in business and everyday writing.

2. When should I use “memoranda” instead of “memorandums”?

Use memoranda in formal, legal, or academic writing where tradition and precision matter. If you are writing a legal brief, a scholarly article, or an official government document, memoranda is often the expected form. In all other situations, memorandums is fine.

3. Can I use “memo” as a plural?

Yes. Memo is a shortened form of memorandum, and its plural is memos. This is very common in business and is acceptable in both formal and informal contexts. For example, “I have five memos to read” is clear and natural.

4. What is the plural of “memorandum of understanding”?

The plural of “memorandum of understanding” is either “memorandums of understanding” or “memoranda of understanding.” The same rules apply: use memorandums for general writing and memoranda for formal contexts. For example, “The companies signed several memorandums of understanding” or “The companies signed several memoranda of understanding.”

Final Thoughts

Choosing between memorandums and memoranda does not have to be stressful. For most business writing, memorandums is the safe, clear, and natural choice. If you are in a formal setting or following a specific style guide, memoranda may be preferred. And when in doubt, memos is always a reliable alternative. The key is to match the tone of your document and your audience. With practice, you will use both forms confidently.

For more help with plural forms, visit our Common Plural Forms section or check out our FAQ for answers to other common questions. If you have specific questions about your writing, feel free to contact us. We are here to help you write with clarity and confidence.