The correct spelling is definitely—with -ite- in the middle. The most common slip is definately (wrong), and another frequent mix-up is defiantly (a different word). If you’re here because you want the right form fast, you’re in the right place.
Quick Answer
Meaning check: definitely is about certainty or a strong yes. Defiantly is about resistance or doing something in a bold, challenging way.
Correct Spelling and Meaning
- Word
- definitely (adverb)
- Core Meaning
- Used to show certainty (“without doubt”) or a firm yes in speech.
- Standard Spelling
- def-i-nite-ly (notice the -nite- chunk)
The standard dictionary spelling is definitely, and it’s listed with the syllable pattern def·i·nite·ly. That “nite” sound is part of what your eye can lock onto when you’re checking the letters.✅Source
Pronunciation can also push people toward the wrong vowels because the middle syllable often sounds reduced in quick speech. Britannica’s audio transcription shows /ˈdɛfənɪtli/, which helps explain why the word feels like it’s missing a clear second “i” when you say it fast.✅Source
Why It Gets Misspelled
Definitely is a perfect storm of sound vs. spelling. In everyday speech, the middle vowels can blur, and your brain tries to “repair” the word into a familiar pattern like -ate- or a shorter -atly ending.
- Reduced vowels: the spoken rhythm can hide the second “i” in the written form.
- Pattern pressure: English has lots of -ate words, so definately can feel “right” at a glance.
- Autocorrect misses: informal typing habits make definatly look normal in chats, so the wrong form becomes visually familiar.
This is also a word people type quickly because it often appears as a strong agreement (“Yes, definitely”). Speed plus a soft middle syllable is enough to create a repeatable spelling slip.
Common Wrong Spellings You’ll See
Here are the usual suspects. Each one has a reason it happens, even though the final result is still incorrect. The fastest visual check is whether the word keeps the -nite- sequence.
| Spelling | Status | Why It Feels Plausible | What To Notice |
|---|---|---|---|
| definitely | ✅ Correct | Matches the base word definite + -ly | Contains -nite- and ends in -ly |
| definately | ❌ Wrong | Feels like other -ate spellings | Swaps -ite- for -ate- |
| definatly | ❌ Wrong | Shortens the middle because speech is compressed | Missing the second “e” and the i |
| definetly | ❌ Wrong | Keeps -ly but guesses the vowel pattern | Has -net- instead of -nite- |
| definatley | ❌ Wrong | Over-corrects with extra letters for “flow” | Extra a/e doesn’t exist in the standard form |
| definatelly | ❌ Wrong | Doubles letters because the ending sounds “heavy” | Only one l appears before -y |
If you only remember one visual cue, make it this: definitely contains defi + nite + ly. The wrong versions almost always damage the -nite- part.
Built From “Definite” + “-ly”
One reason definitely is easier to trust on paper is its structure. The base adjective is definite, and the adverb form adds -ly. That’s why the correct spelling keeps the i from definite rather than drifting into -ate-.✅Source
- definite (adjective)
- definitely (adverb)
- definiteness (noun)
This is also why “definate” is a dead end. If the base word is spelled definite, then definitely follows that spelling logic. The family resemblance is real, even when the spoken rhythm makes it harder to hear.
Usage Notes That Affect Spelling
Definitely does two jobs in modern English. One is straightforward: it marks certainty (“It will definitely happen”). The other is conversational: it works as a strong yes (“Definitely!”). Both uses are standard, and neither changes the spelling.
A Common Meaning Mix-Up: “Definitely” vs. “Defiantly”
Definitely = certainly, without doubt. Defiantly = in a way that shows defiance. The spellings look close, so writers sometimes grab the wrong one when typing fast.
- ✅ Definitely: “Yes, I’m definitely coming.”
- ✅ Defiantly: “He answered defiantly.”
If your sentence is about certainty, the spelling is definitely. If it’s about pushback or resistance, the spelling is defiantly. That meaning check is often faster than staring at the vowels.
Examples in Real Sentences
These examples keep the focus on spelling and usage. Notice how the correct form stays identical, whether it’s calm or emphatic.
✅ Correct Uses
- “I will definitely email you today.”
- “That is definitely the right file.”
- “Are you joining us?” “Definitely!”
❌ Incorrect Uses
- “I will definately email you today.”
- “That is definetly the right file.”
- “Are you joining us?” “Definatly!”
A small spelling detail with a big payoff: the ending is always -ly, and there’s no extra e wedged in before the y. If you see -lley or a doubled ll, it’s almost certainly a typo rather than a valid variant.
FAQ
Frequently Asked Questions
Is “definately” ever correct?
No. Definately is a misspelling of definitely. In edited English, definately isn’t treated as a standard variant.
What’s the simplest way to recognize the correct spelling?
Look for the -nite- chunk inside definitely. Most wrong versions replace it with -nate- or drop letters to make a shorter shape.
Is there any difference between US and UK spelling for “definitely”?
No. Definitely is spelled the same in American and British English, and it keeps the same -ly ending.
Why do people confuse “definitely” with “defiantly”?
The words share a similar outline and start with def-, so a quick glance can trick you. Meaning is the clean separator: definitely signals certainty; defiantly signals defiance.
Can “definitely” be used as a standalone answer?
Yes. In conversation, Definitely! works as a strong yes. The spelling stays exactly the same as the adverb form in a full sentence.
Does “definitely” have one “l” or two?
It has one l before the y: definite + ly → definitely. Spellings like definatelly are nonstandard typos.