In American English, always use inquire. In British and Australian English, the traditional rule is enquire for a general question and inquire for a formal investigation — but most native speakers and style guides treat the two forms as interchangeable.
The American English Rule
If you’re writing for an American audience, this is simple: use inquire and inquiry in every situation.
She emailed the recruiter to inquire whether the remote-work policy applied to her new role.
The patient called the clinic to inquire about her MRI results.
American dictionaries back this up. Merriam-Webster lists enquire as “chiefly British” and points straight back to inquire. Using enquire in American writing isn’t technically wrong, but it looks unusual enough that some editors will flag it as a typo.
The British and Australian Rule — and Where It Softens
In the UK and Australia, two forms are in everyday use, and careful writers apply this distinction:
- Enquire / enquiry — a general question or request for information
- Inquire / inquiry — a formal or official investigation
A few examples that show the distinction working cleanly:
| Situation | Preferred Form |
|---|---|
| Asking a hotel about room rates | enquire |
| Asking your GP about a test result | enquire |
| A government body examining wrongdoing | inquire |
| A judge-led public investigation | inquiry |
| Police examining a crime | inquiry |
In practice, many British and Australian writers mix the forms freely, especially in informal writing. Corpus data shows the distinction is real but leaky. More on that below.
How Two Spellings Ended Up in the Language
Both forms came from the same source — which is why neither one is a mistake.
The word entered English around 1300 from the Old French enquerre, meaning “to ask.” The very first English spelling used en-. Then, in the 14th century, scholars noticed that the original Latin verb was inquirere and started respelling the word with in- to match it. This kind of backwards correction — changing a living word to look more like its Latin ancestor — was common at the time.
The result: both spellings survived. Samuel Johnson backed inquire in his 1755 dictionary and left out the en- forms entirely. His preference didn’t win. British English kept both, roughly side by side.
The in- spelling won completely in American English. The en- spelling held on in British and Australian English, especially for informal use.
The two words sound almost identical in natural speech. Only if you enunciate carefully does a difference appear: inquire opens with the vowel in “tin” (ˈɪ/); enquire with the vowel in “ten” (/ɛ/). Most listeners won’t notice either way.
What Dictionaries and Corpora Actually Show
The real picture is more layered than most grammar pages suggest.
Dictionary Positions
| Source | What It Says |
|---|---|
| Merriam-Webster | Enquire = “chiefly British” variant; no formal/informal distinction made |
| Oxford Learner’s Dictionaries | Notes the British distinction but says either spelling works in either meaning |
| Collins English Dictionary (2012) | Enquire = a variant of inquire; British speakers may prefer enquire in less formal contexts |
| Macquarie Dictionary (Australia) | Places entry under inquire; acknowledges both forms as interchangeable |
Corpus Data
The most useful numbers come from linguist David Crystal’s analysis of two large corpora:
- Cambridge Corpus of American English: 97% of uses were inquire, 88% were inquiry — dominant, but not 100%.
- British National Corpus (BNC): About twice as many enquire as inquire for the verb — but twice as many inquiry as enquiry for the noun.
That second finding is worth pausing on. British writers tend to say enquire but write inquiry. In other words, they already favor the in- noun even when they use the en- verb. Crystal’s conclusion: for most people, the forms are “as interchangeable as judgment and judgement — influenced by region, house style, and institutional preference, but not by anything semantic.”
The Grey Zone: Cases That Don’t Fit Neatly
The formal/informal rule sounds clean until you hit real situations.
A scientist who “investigates” something — is that formal enough for inquire? Most academic writing follows the house style of the journal, not the enquire/inquire distinction.
A journalist “looking into” a story — informal writing, but possibly a serious investigation. The Guardian, a British newspaper, resolves this by requiring inquire and inquiry for everything — even though the distinction technically allows enquire for an informal question.
A business email or “contact us” page — UK companies routinely label customer contacts “enquiries” (as in, “send your enquiries to help@example.co.uk”). That’s standard commercial British English. But a US company would write “send your inquiries.”
A UK legal document or public investigation — always inquiry, never enquiry. The Leveson Inquiry examined press standards after the phone-hacking scandal. That naming is standard; “Leveson Enquiry” would look wrong to British lawyers and civil servants. When the form matters, it’s almost always inquiry that’s required.
If you’re unsure, ask yourself: Is this naming an official process or institution? If yes, use inquiry. If it’s a question one person is asking, either form works in British/Australian English.
The Inquest, Inquisitive, Inquisition Argument
Some writers argue that inquire is the “logical” choice because all the related English words use in-:
- inquest
- inquisitive
- inquisition
- inquisitor
None of them exist in an en- form. So inquire and inquiry fit this family; enquire and enquiry sit apart from it.
This is a reasonable consistency argument, not a grammar rule. It’s worth knowing, especially if you’re a student or non-native speaker deciding which form to learn.
Noun Forms: Inquiry and Enquiry
Everything above applies equally to the nouns.
- Inquiry — standard in American English; used in British/Australian English for formal investigations
- Enquiry — British/Australian English for general questions
The inconsistency you’d want to avoid:
“I will enquire and then submit an inquiry.”
That mixes British and American styles in one sentence. Pick one and use it throughout — the same way you’d pick colour or color and stay with it.
What Style Guides Say
Most large news organizations have resolved the question by picking one form for everything.
- The Guardian (British): requires inquire and inquiry
- Fairfax Media (Australian): prescribes only the i- forms
- Most US journalism guides favor inquire
The pattern is clear: when organizations make a house decision, they almost always land on the in- forms — even British ones. The en- forms survive mainly in informal British writing and institutional naming (customer enquiries desks, general enquiries lines).
Quick Decision Guide
American English: Use inquire / inquiry for everything.
British or Australian English:
- Is it an official investigation, a public body, or a legal process? → inquire / inquiry
- Is it a general question — asking about hours, prices, details? → enquire / enquiry
- Are you unsure which it is? → inquire / inquiry — it’s always accepted in both senses and matches most style guides.
- Does your publication or employer have a house style? → Follow that style and ignore the rest.
The one rule that applies everywhere: don’t mix forms in the same document. If your document uses enquire in the first paragraph, don’t switch to inquiry by the third.
The safest default — wherever you’re writing — is inquire and inquiry. They work in every variety of English, fit every major style guide that has taken a position, and belong to the same word family as inquest and inquisitive. The difference between enquire and inquire is real in careful British writing, but it’s one of preference more than rule.
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I’m Hazel, and I studied BSC English at GCUF. I focus on explaining word meanings in simple, clear language that anyone can understand. My goal is helping readers grasp everyday English, confusing terms, and slang used in real conversations and social media. I believe language learning works best when definitions connect to actual life situations. Through careful research and straightforward explanations, I make vocabulary accessible for students, learners, and anyone curious about how English really works in daily use.