Catalogue or Catalog? UK vs US
Here's a small family of spellings that quietly trips people up the moment a document crosses the Atlantic. You write catalogue, someone on a US team rewrites it catalog, and suddenly you're both wondering who owns the word. Then the most confident non-writer in the room announces that one of you is plainly wrong.
The good news is that nobody's born knowing this, and the picture is calmer than it looks. Some of these words genuinely differ between British and American English. A few are basically settled on both sides. And one or two, like dialogue, are sitting right in the middle of a long, slow change.
This is a quick side-by-side, not a lesson. No new rules — just the map, the honest exceptions, and a way to choose without second-guessing yourself. For the wider story on how British and American spelling systems fit together, see the related guides below.
The -ogue / -og family at a glance
| UK spelling (-ogue) | US spelling (-og) | Example |
|---|---|---|
| catalogue | catalog | She checked the museum catalogue [US: catalog] for the painting. |
| analogue | analog | An analogue [US: analog] clock has hands; a digital one doesn't. |
| dialogue | dialogue (prose) / dialog (tech) | The film's dialogue is razor-sharp; then a "Save As" dialog box appears. |
| monologue | monologue (usual) / monolog (rare) | Hamlet's monologue still lands. |
| prologue | prologue (usual) / prolog (rare) | The novel opens with a short prologue. |
| epilogue | epilogue (usual) / epilog (rare) | The epilogue ties up the loose ends. |
| travelogue | travelogue / travelog | Her blog reads like a travelogue of Japan. |
One warning before you trust the pattern too far: not every -ogue word flips. Synagogue, pedagogue and demagogue keep their tails on both sides of the ocean. The only pairs that reliably change in everyday writing are catalogue / catalog and analogue / analog. The rest mostly stay as -ogue, whichever coast you're on.
The honest bit: meaning splits and mixed usage
Most of these are pure spelling swaps. Same meaning, different letters — a British catalogue and an American catalog are the same object. But a couple of the words have wandered, and those are worth knowing.
Analogue and analog. In UK English, analogue is the standard across the board — the clock face, the recording, the older "something that corresponds to something else." In US English, analog is the everyday and technical default. The wrinkle is that analog has quietly become the global working form in tech and engineering, so you'll find British writers reaching for analog synthesiser even in otherwise British copy, especially deep in hardware documentation. That's styling for the room, not a change of heart about British spelling.
Dialogue and dialog. This is the one that refuses to sit still. American English still uses dialogue for people talking — film dialogue, a tense exchange between characters, a "constructive dialogue" at work. Dialog is the specialised tech spelling: a dialog box, a dialog window in software. Plenty of US publishers keep dialogue for prose and reserve dialog for computing alone. UK English sticks with dialogue almost everywhere, and only borrows dialog when following a product's own UI wording.
Catalogue and catalog. No hidden meaning here, just house taste. American libraries, retail and software tend to run with catalog; British ones with catalogue.
Common Mistake: Assuming every American writer prefers the short form. They don't. Dialogue, prologue, monologue and epilogue are still home territory for a great deal of American fiction and journalism. Your spellchecker's suggestion is not the final word.
Pro-Tip: In UI copy and technical docs written for mixed teams, many houses standardise early on dialog, analog and catalog to match North American platforms — even when the surrounding prose stays British. Agree it once, then stop renegotiating every time.
Which am I writing today?
You don't want a history lecture; you want the document finished without looking careless. Three short questions will settle almost every case.
- Whose house style or audience owns this piece? British school, employer or publisher, or mainly UK readers → the full -ogue forms. US employer, publisher or readers → catalog and analog, and dialog when you specifically mean a software box.
- Is it creative writing or something that lives on a screen? Fiction, essays and general correspondence take the -ogue forms in UK English. Interface strings, release notes and hardware specs often take the short -og forms by convention, whichever side you're on. Flag the choice; don't fight every string.
- Is there already a documented house list? If the style guide has locked catalogue — or catalog — use their word. Your job is a consistent read for the reader, not a personal crusade for one spelling tribe.
Once you've picked, stay with it for the whole piece. Switching mid-email from catalogue to catalog doesn't look clever; it looks unfinished. The same goes for a slide deck, a help-centre article or a novel. A quick find-and-check pass at the end — searching both spellings, making sure they've all landed the same way — mops up the strays.
Pick one, and stay consistent. That single habit does more work than memorising every rare -og form. Readers forgive a legitimate national variant far quicker than they forgive flip-flopping inside one piece of writing.
Key Takeaways
- Most -ogue / -og pairs are spelling twins: catalogue / catalog, analogue / analog, travelogue / travelog.
- Catalogue / catalog and analogue / analog are the two splits you'll actually meet every day.
- Dialogue survives in US prose for conversation; dialog is the common tech and UI form.
- Analogue is the UK default; analog is the US — and much of tech-global — default.
- Prologue, monologue and epilogue keep their tails in most American writing too; the short forms are rare variants.
- Synagogue, pedagogue and demagogue don't change at all.
- Choose by audience and house style, then lock it for the whole document.
Related guides
- [A6a] — UK -ogue and the British spelling forms (the fuller picture on the -ogue side)
- [A6b] — US -og and the American spelling forms (the fuller picture on the -og side)
- [A0] — UK vs US spelling: how the systems fit together (the master overview)
Nobody expects you to carry the whole table in your head. Keep this page handy, check the room you're writing for, pick once — and get back to the sentence that actually matters.