Definitely or Definately: Which Spelling Is Correct?

When writing an email, school assignment, or social media post, you may stop at definitely or definately and wonder which one is correct.

The answer is simple: definitely is the correct spelling, while definately is a common misspelling. The correct word is an adverb that means “without any doubt” or “certainly.” (Cambridge Dictionary)

The confusion is easy to understand. The word is pronounced quickly, so the middle vowels can be hard to hear. Also, the related word definite can make the spelling easier to remember.

This guide explains the correct spelling, origin, pronunciation, common mistakes, British and American usage, and simple examples.

Quick Answer

Definitely is the correct spelling. Definately is incorrect.

Use definitely when you mean “without doubt,” “certainly,” or “surely.”

Correct: I will definitely call you tomorrow.
Incorrect: I will definately call you tomorrow.

Oxford and Cambridge both list definitely as the standard English form. (Oxford Learner’s Dictionaries)

The Origin of Definitely

The spelling becomes easier to understand when you look at the word definite.

Definitely comes from definite + -ly. The word has been used in English since the 1580s. Its base, definite, comes from Latin definitus, meaning “defined, bounded, or limited.” (Etymology Online)

The spelling definitely keeps the connection to definite:

definite → definitely

The incorrect form definately is not a British or American spelling variant. It is simply a common spelling error.

British English vs American English Spelling

There is no difference in spelling between British English and American English for this word.

Variety	Correct Spelling	Incorrect Spelling
British English	definitely	definately
American English	definitely	definately
Canadian English	definitely	definately
Australian English	definitely	definately

So, no matter which major English variety you use, write definitely.

The pronunciation can vary slightly between British and American English, but the spelling stays the same. (Cambridge Dictionary)

Pronunciation of Definitely

The correct pronunciation is roughly:

DEF-in-it-ly

Cambridge gives the UK pronunciation as /ˈdef.ɪ.nət.li/ and the US pronunciation as /ˈdef.ə.nət.li/. (Cambridge Dictionary)

The spoken word may sound like “def-in-it-lee.”

This helps explain the spelling confusion. When people say the word quickly, some of the middle sounds become less clear. That can lead writers to insert an a and produce the incorrect form definately.

Remember: the spelling is based on definite, not on how every sound appears in fast speech.

Why People Confuse Definitely or Definately

There are several reasons people mix these forms up.

1. Fast pronunciation
The word has several syllables, and the middle vowel sounds can be weak in normal speech.

2. The letters sound similar
The sequence of vowels is easy to mix up when writing from memory.

3. The word is often used in casual writing
People may type quickly in messages and social media posts.

4. The base word is easy to overlook
Remembering definite makes the correct spelling much easier.

5. Spelling memory can follow pronunciation
English spelling is not always a direct copy of spoken sounds.

The key point is that definately may look natural, but it is not the standard spelling.

Which Spelling Should You Use?

Use definitely in all standard English writing.

It is suitable for:

School and academic writing
Emails
Business communication
News writing
Social media
Everyday messages
Formal documents

You do not need a separate American or British version.

Definitely is the global standard form. (Oxford Learner’s Dictionaries)

Common Mistakes with Definitely or Definately

Incorrect	Correct	Example
definately	definitely	I will definitely come.
definatly	definitely	She definitely knows.
definitly	definitely	We definitely need help.
definetely	definitely	He is definitely ready.
definetly	definitely	I definitely agree.

The most common error is definately, but several other versions can appear when people spell the word by sound.

A useful rule is simple: If you can spell definite, you can spell definitely.

Definitely in Everyday Examples

Email:
“I will definitely send the report by Friday.”

Here, definitely shows strong certainty.

News writing:
“The new policy will definitely affect many businesses.”

The writer is emphasizing confidence in the statement.

Social media:
“That is definitely the best movie I have seen this year.”

The word adds strong emphasis.

Formal writing:
“The results definitely show a change in consumer behavior.”

Here, the word works in formal English as well.

Everyday conversation:
“Are you coming with us?”
“Definitely!”

Cambridge notes that definitely can also be used as a short response to show strong agreement or certainty. (Cambridge Dictionary)

Easy Trick to Remember Definitely

Use this simple memory trick:

DEFINITE + LY = DEFINITELY

First write:

DEFINITE

Then add:

That gives you:

DEFINITE + LY → DEFINITELY

Think of the phrase:

“It is definitely definite.”

The important part is FINITE:

de + finite + ly → definitely

This can help you avoid adding the incorrect a found in definately.

Definitely or Definately – Google Trends & Usage Data

Search interest for spelling questions can vary by country and over time, so exact Google Trends numbers should be checked for the specific region and date range being studied.

The more important usage fact is clear: definitely is the established standard spelling in English dictionaries, while definately is a misspelling. Oxford and Cambridge both use definitely as the dictionary headword. (Oxford Learner’s Dictionaries)

There is also no British-versus-American spelling split. Both varieties use definitely.

For SEO and writing purposes, treat definitely as the correct word and definately as a common spelling error.

Definitely vs Related Words

Word	Meaning	Example
Definitely	Without doubt	I will definitely go.
Certainly	Without doubt; surely	She will certainly help.
Surely	Very likely or certainly, often seeking agreement	Surely you know him.
Undoubtedly	Clearly without doubt	He is undoubtedly talented.

These words can overlap in meaning, but they are not always interchangeable in tone or sentence structure. Oxford lists certainly as a close synonym of definitely, while surely can carry a slightly different sense or expectation. (Oxford Learner’s Dictionaries)

FAQs

Is definitely or definately correct?

Definitely is correct. Definately is a misspelling.

How do you spell definitely?

Spell it D-E-F-I-N-I-T-E-L-Y.

Why is definitely so often misspelled?

Its pronunciation can make the middle vowels difficult to hear, and people often write what they think they hear.

Is definately a word?

No. Definately is not the standard English spelling. Use definitely instead.

Is definitely spelled differently in British English?

No. British and American English both use definitely.

What does definitely mean?

It means “without any doubt” or “certainly.” (Cambridge Dictionary)

How can I remember the spelling?

Think DEFINITE + LY = DEFINITELY. The base word definite contains the letters you need.

Key Takeaway

Definitely is the only correct spelling in standard English. Definately is a common misspelling, not an alternative British or American form.

The easiest way to remember the word is to connect it with definite: definite + ly = definitely.

Use definitely in emails, academic writing, professional communication, social media, and everyday English whenever you want to express certainty or strong agreement.