Plural of “memo”

The plural of memo is memos.

Why

"Memo" is a 20th-century clipping of "memorandum," itself Latin for "a thing to be remembered." Like "photo," it entered English as an informal shortening of a longer, more formal word, and clipped words in English take a plain -s plural essentially without exception.

Interestingly, the full word "memorandum" it was clipped from has its own genuinely competing plurals, "memoranda" and "memorandums," reflecting its Latin -um origin — but "memo," as a separate, later clipped form, never inherited any of that Latin plural complexity, because it was built fresh in English as an everyday office-speak shortcut. Dictionaries first recorded "memo" as a standalone word in the early 20th century, roughly contemporary with a broader wave of shortened business vocabulary, including "ad" for advertisement and "exec" for executive, that emerged as American corporate culture expanded rapidly and favored brisk, efficient jargon.

Usage note

"Memos" is correct in every context, from casual office slang to formal business writing that has adopted the shortened form. "Memo" also functions informally as a verb in some workplace jargon ("just memo me the details"), a casual back-formation that hasn't made it into most dictionaries but shows up often enough in spoken corporate speech.

"Memo" rose to particular prominence in American office culture over the 20th century as a specific genre of short, informal internal communication distinct from formal letters, and its clipped brevity mirrored the document type itself: quick, unceremonious, meant to be read fast. Email and instant messaging have largely displaced the physical paper memo in most modern workplaces, yet the word "memo" persists as the label for a short, focused internal message even when it's sent digitally rather than printed and circulated on paper the way it once was.

Common real mistakes

The main point of confusion isn't the plural of "memo" itself, which is straightforward, but writers sometimes conflate it with the plural rules for its parent word "memorandum," mistakenly assuming "memo" should also have a Latin-style plural — it never did, since it's a modern English clipping, not a direct Latin borrowing. A separate, purely stylistic issue is overusing "memo" as a catch-all term for any internal document, when more precise formal writing might distinguish memos from reports, briefs, or bulletins based on length and purpose.

The wider pattern

"Memo" and "photo" are twins in how they pluralize: both are 20th-century clippings of longer, more formal words, and both simply add -s, unlike their more classically rooted full-length source words, which sometimes carry their own separate plural complications.

Examples

• The manager sent out three memos about the schedule change.
• Old memos from the merger were archived in a locked cabinet.
• She wrote quick memos summarizing each meeting.
• Employees ignored most of the memos about the dress code.
• The office was flooded with memos after the policy change.
• He kept every memo from his first year on the job.
• New memos went out to all department heads on Monday.
• The lawyer drafted several memos outlining the case strategy.
• Internal memos revealed the company's plans months in advance.
• Handwritten memos still cluttered his desk despite the new software.
• The auditor requested copies of all memos related to the transaction.
• Weekly memos kept remote staff updated on project deadlines.
• The archive contains hundreds of memos from the company's founding decade.
• She filed the old memos alphabetically by department.
• The intern proofread every memo before it went out to clients.
• Department memos were consolidated into a single weekly digest.
• Legal teams archive every memo related to an active case.
• The board reviewed the memos before the quarterly meeting began.
• The startup switched entirely to digital memos last year.
• He drafted a short memo summarizing the budget changes.