Analysed or Analyzed: British vs American Spelling

Analysed or analyzed? Both spellings are correct — and both are wrong, depending on where your reader lives. This is not a case of one right word and one misspelling. It is a case of two standard spellings of the same verb, divided by the Atlantic, and the mistake is not choosing one of them but mixing them up, or using the wrong one for your audience.

This guide explains what the verb means, which spelling belongs to British English and which to American English, how the whole family of forms works, and how to stay consistent once you have chosen.

What Does Analyse / Analyze Mean?

Cambridge Dictionary defines the verb — under the headword analyse, marked “UK (US analyze)” — as “to study or examine something in detail in order to discover or understand more about it”. Its example is literary and concrete: “The book brilliantly analyses the cultural struggles taking place in America during the 1960s.” A second sense covers the scientific use: to examine a substance, especially by separating it into its parts, in order to discover what it is or contains.

Merriam-Webster, under analyze, gives the same meaning from the American side: to examine methodically by separating into parts and studying their interrelations. The noun behind the verb is analysis, spelled the same in both varieties, and the verb is a back-formation from that noun — a point Dictionary.com records, dating the verb to the late 16th and early 17th centuries.

In ordinary use, analyse covers a wide range: a scientist analyses data, a critic analyses a poem, a business analyses its sales, a doctor analyses test results. In every case the meaning is the same — careful, detailed examination in order to understand — and only the spelling of the verb changes with the variety of English.

The -yse / -yze Rule

The difference between analysed and analyzed is one instance of a larger pattern. British English spells a small group of verbs with -yse where American English uses -yze:

British English	American English	Meaning
analyse	analyze	examine in detail
paralyse	paralyze	cause loss of movement
catalyse	catalyze	speed up a chemical reaction
dialyse	dialyze	purify blood by dialysis

The pattern is small — only a handful of common verbs end in -yse / -yze — but the words in it are frequent in academic, scientific, and business writing, so the choice comes up often. The related -ise / -ize pattern (organise/organize, realise/realize) is much larger and works differently: Oxford spelling, used by Oxford University Press and many international organisations, actually prefers -ize even in British English, because it reflects the Greek origin. That exception does not apply to -yse words. As the Universitat Pompeu Fabra’s guide to Oxford spelling notes, words ending in -yse such as analyse are written with an “s” in both British and Oxford spelling, and only American English uses “z”. So analyze is American in every standard; analyse is British in every standard, including Oxford spelling.

The history is straightforward. The “s” spelling came into British English through French influence — the French Academy made the “s” spelling standard in 1694, and British English followed. American English, under Noah Webster’s reforms in the early 19th century, returned to the “z”, which is closer to the original Greek zeta. Neither spelling is a corruption; they are two different decisions about the same Greek root, made two hundred years apart.

How to Pronounce Analyse and Analyzed

Here the two varieties agree completely. Cambridge gives the pronunciation of analyse as UK /ˈæn.əl.aɪz/ and US /ˈæn.əl.aɪz/ — identical. The past forms are pronounced the same way in both varieties too: /ˈæn.əl.aɪzd/. The “s” in analysed and the “z” in analyzed are both pronounced as a “z” sound, /z/, so the ear cannot tell the spellings apart at all.

That is an important point for learners and for writers working from dictation. If you hear /ˈæn.əl.aɪzd/, you cannot know from sound alone whether the writer intended analysed or analyzed. The spelling has to be chosen by audience, not by ear. The same is true of the whole family: analysing / analyzing, analyser / analyzer, analysis (the same in both).

The Whole Family: Keep Every Form Consistent

The most common error with this pair is not choosing the wrong spelling once, but mixing the two spellings in a single document. A report that says “we analysed the data” on page one and “we analyzed the results” on page three looks careless, even though each sentence on its own is correct. Consistency is the real rule.

Form	British English	American English
Infinitive	analyse	analyze
Past tense	analysed	analyzed
Past participle	analysed	analyzed
-ing form	analysing	analyzing
Third person singular	analyses	analyzes
Person who does it	analyser	analyzer
Noun	analysis	analysis

Notice the trap in the third person singular: British analyses is spelled exactly like the plural of the noun analysis — “two analyses of the data” and “she analyses the data” are spelled identically, though they are pronounced differently (the noun is /əˈnæl.ɪ.siːz/ in its plural, the verb is /ˈæn.əl.aɪ.zɪz/). Context is the only guide, and it is usually enough.

Consistency should extend beyond this one verb. If you choose British English, use organise, behaviour, and centre alongside analysed. If you choose American English, use organize, behavior, and center alongside analyzed. A document that mixes analysed with organize is inconsistent in a way a reader will notice, even if they cannot name the rule.

Analysed or Analyzed in Real Sentences

• British: The team analysed the survey results before the meeting.
• American: The team analyzed the survey results before the meeting.
• British: She analysed the poem line by line.
• American: She analyzed the poem line by line.
• British: The lab is analysing the samples now.
• American: The lab is analyzing the samples now.
• Both: The book brilliantly analyses the cultural struggles of the 1960s. (British verb form; American would be analyzes.)

Correct vs Incorrect

Incorrect (for the audience)	Correct	Why
British report: “We analyzed the data.”	British report: “We analysed the data.”	American spelling in a British document.
American essay: “She analysed the results.”	American essay: “She analyzed the results.”	British spelling in an American document.
One document: “analysed … analyzed …”	One spelling throughout.	Mixing varieties looks careless.
“He analyzis the data.”	“He analyzes the data.” (US) / “He analyses the data.” (UK)	Analyzis is not a form of the verb.
“The data was analyze.”	“The data was analysed / analyzed.”	Past participle needed after was.

Common Mistakes to Avoid

1. Treating one spelling as a misspelling

Neither analysed nor analyzed is wrong in itself. A spellchecker set to the wrong variety of English will flag the other spelling, and that flag means “wrong for this setting”, not “wrong in English”. Check your language setting before you accept a correction.

2. Mixing spellings in one document

This is the most frequent real-world error. Pick a variety at the start — British or American — and apply it to every -yse / -yze verb and to the rest of the document’s spelling. A find-and-replace for “analyze” and “analysed” at the end of a draft catches most slips.

3. Writing “analyzis” or “analysys”

The verb is analyse / analyze; the noun is analysis. There is no verb form analyzis and no noun analysys. The third person singular of the British verb is analyses, which is easily confused with the plural noun — check the sentence’s grammar, not just the letters.

4. Using “analyse” in American English as a deliberate choice

In American English, analyse is treated as a misspelling, not as an acceptable variant. Quillbot’s usage guide puts it plainly: in American English, analyze is the only correct spelling. The reverse is true in British English, where analyzed is the form a British reader will mark as wrong. There is no middle ground to hide in — choose by audience.

5. Forgetting Canada and Australia

Canada generally follows American spelling for this verb and uses analyzed, while Australia and New Zealand follow British spelling and use analysed. If you are writing for an international audience, state the variety you are using or follow the style guide of the publication, and then stay consistent.

How to Choose

Ask where your reader is, or which style guide governs your writing. A British school, university, or publisher expects analysed. An American one expects analyzed. An international journal will usually state its preference in its author guidelines — Oxford spelling, for example, keeps analyse with an “s” while using -ize for words like organize, which surprises writers who assume Oxford spelling is simply British spelling.

If you genuinely do not know your audience, British spelling is often the safer default for an international readership outside North America, and American spelling is the safer default for a North American readership. Either way, the choice matters less than the consistency: a document that uses one spelling throughout reads as a deliberate choice, while a document that mixes them reads as an accident.

A practical memory aid: analyse and British both contain an “s” — or, more precisely, analyse ends in “se” and the word British is spelled with an “s” in the middle. Analyze and American both contain a “z” is less neat, but the pairing “z for the US” is easy to remember once you have heard it: the “z” spelling is the American reform, and Webster’s dictionary made it standard.

FAQs

Is “analysed” or “analyzed” correct?

Both are correct. Analysed is the British spelling and analyzed is the American spelling of the same past tense. The error is using the wrong one for your audience, or mixing them.

Does the meaning change between the two spellings?

No. The meaning is identical: to examine something in detail in order to understand it. Only the spelling changes.

Are they pronounced differently?

No. Both are pronounced /ˈæn.əl.aɪzd/ in British and American English. The “s” and the “z” are both pronounced as /z/.

Is “analyze” acceptable in British English?

It is listed as a variant in some dictionaries, but it is not the preferred British spelling, and a British reader or examiner will usually treat it as an error. In British English, use analyse.

What about “analysing” and “analyzing”?

The same rule applies: analysing is British, analyzing is American. The whole verb family follows the spelling you choose.

Is the noun “analysis” spelled differently too?

No. Analysis is spelled the same in British and American English, and its plural is analyses in both.

The Takeaway

Analysed is British; analyzed is American. The meaning is the same, the pronunciation is the same, and the only mistake is choosing the wrong one for your reader or mixing the two. Pick a variety, apply it to the whole verb family, and keep it consistent to the last page. Confirm the dictionary position at Cambridge’s entry for analyse, which marks the verb “UK (US analyze)”.