for sure
2 antonyms for for sure — opposites grouped by meaning.
Adverb — Without any doubt; certainly.
Synonyms by Meaning
1. adverb informal
Without any doubt; certainly.
“I can't say for sure whether the shop is open on Sundays.”
Opposites
2. interjection informal
Used on its own to agree with someone or accept a request.
“"Can you send it over tonight?" "For sure."”
Antonyms
How to use for sure
The word patterns that sound natural to a native speaker.
know for sure
one thing's for sure
that's for sure
can't say for sure
Conversational. As an interjection it is especially common in North American and Australian speech; formal writing uses certainly or with certainty instead.
Frequently asked questions
What is the difference between for sure and surely?
For sure means with certainty and usually attaches to knowing or saying — "I don't know for sure". Surely expresses the speaker's expectation or appeal for agreement — "surely he told you?" — and in American English can also mean certainly.
Is "for sure" too casual for work emails?
As a one-word yes it is fine among colleagues but reads as offhand to clients or senior staff. Certainly, of course, or a plain confirmation of what you will do is safer in external correspondence.
