Declare vs Say for sure

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

Declare

FormalTop 2,000 (common)B2verb

Say for sure

Top 3,000 (common)
Most formal: DeclareMost common: Declare
 DeclareSay for sure
Pronunciation🇬🇧 /["/dɪˈkleə(r)/","/dɪˈkleəz/","/dɪˈkleəd/","/dɪˈkleərɪŋ/"]/🇺🇸 /["/dɪˈkler/","/dɪˈklerz/","/dɪˈklerd/","/dɪˈklerɪŋ/"]/🇬🇧 //seɪ fə ʃʊə//🇺🇸 //seɪ fɔr ʃʊr//
MeaningTo say something officially or publicly.To confirm something definitely.
ExampleThe president will declare the new policy during the press conference.I can say for sure that we'll finish on time.
RegisterFormalNeutral
How commonTop 2,000 (common)Top 3,000 (common)
CEFR levelB2-
Part of speechverb
Collocationsvirtually, immediately, promptly, to, virtually, immediately, promptly, tosay for sure something, say for sure that, can say for sure, must say for sure, don't know for sure
Antonymsdeny, disclaim, suppress-
Common mistakesUsing 'declare' without an object (e.g., 'I declare' alone is often incomplete), Confusing 'declare' with 'proclaim' which has a different nuance, Saying 'declaring for' instead of 'declaring to be' when stating identity or statusUsing 'say for sure' without a clause, e.g., 'I say for sure it is.', Confusing with similar phrases like 'say definitely'., Incorrectly using in very formal contexts.
Usage notesUsed in formal contexts such as legal, government, or academic settings. Avoid in casual conversations. Commonly used when making announcements or stating intentions.Use in informal or casual contexts to express certainty. Not suitable for formal writing or speeches.

See it in real clips

Declare
Say for sure

Frequently asked questions: Declare vs Say for sure

What's the difference between Declare and Say for sure?

Declare: To say something officially or publicly. Say for sure: To confirm something definitely.

Which is more formal: Declare and Say for sure?

Declare is the most formal of these.

Which is more common: Declare and Say for sure?

Declare is the most common in everyday English.

Can you show an example of each?

Declare: The president will declare the new policy during the press conference. Say for sure: I can say for sure that we'll finish on time.

Can I use Declare and Say for sure interchangeably?

Not always. Declare and Say for 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.

Related comparisons