Definitely vs Yeah sure

When to use each in English, with meaning, register, and examples.

Definitely

Top 1,000 (very common)A2adverb

Yeah sure

InformalBeyond 10,000 (less common)
Most formal: DefinitelyMost common: Definitely
 DefinitelyYeah sure
Pronunciation🇬🇧 /["/ˈdefɪnətli/"]/🇺🇸 /["/ˈdefɪnətli/"]/🇬🇧 //jɛː ʃʊə//🇺🇸 //jæ ʃʊr//
MeaningFor sure, without a doubtA way to agree or say yes casually.
ExampleI definitely remember sending the letter.Can you help me with this project? Yeah sure!
RegisterNeutralInformal
How commonTop 1,000 (very common)Beyond 10,000 (less common)
CEFR levelA2-
Part of speechadverb
Collocationsdefinitely agree, definitely believe, definitely knowYeah sure, why not, Yeah sure, I'll do it, Yeah sure, let's go
Antonymsdoubtfully, uncertainly-
Common mistakesOften confused with 'defiantly' which means resisting authority., Sometimes spelled incorrectly as 'definately'.Using in formal contexts, like job interviews., Confusing with 'yes' in all situations., Not using appropriate tone to convey enthusiasm.
Usage notesUse 'definitely' to emphasize certainty. It fits well in both spoken and written English. Avoid using it in overly formal contexts where alternatives like 'certainly' might be more suitable.Used in informal conversations to agree. Avoid in formal settings. Shows enthusiasm or casual acceptance.

See it in real clips

Definitely
Yeah sure

Frequently asked questions: Definitely vs Yeah sure

What's the difference between Definitely and Yeah sure?

Definitely: For sure, without a doubt Yeah sure: A way to agree or say yes casually.

Which is more formal: Definitely and Yeah sure?

Definitely is the most formal of these.

Which is more common: Definitely and Yeah sure?

Definitely is the most common in everyday English.

Can you show an example of each?

Definitely: I definitely remember sending the letter. Yeah sure: Can you help me with this project? Yeah sure!

Can I use Definitely and Yeah sure interchangeably?

Not always. Definitely and Yeah sure are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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