Sure Of: Standard Pattern
Sure Of: Standard Pattern records a directly documented English construction and keeps guidance bounded to the evidenced pattern rather than turning one attested complement into a universal prohibition.
Use “sure of” when expressing confidence or certainty about something, including confidence that an outcome will occur.
Key details
Choose the right form
| Meaning | Pattern | Decision |
|---|---|---|
| confidence or certainty about a thing or outcome | sure of + noun / -ing | Use the documented construction. |
| certainty expressed as a full proposition | sure (that) + clause | Use a clause when it better expresses the proposition. |
| topic-oriented wording | sure about + noun | Recognize the documented “of/about” boundary rather than treating “of” as universally mandatory. |
Quick tests
Certainty test
Does the complement name the thing, result, or action about which someone feels confident?
If yes: “Sure of” is a documented choice.
If no: A clause or “sure about” may fit other sentence shapes; choose according to the intended construction.
Caveat: The reviewed source documents “sure of” and also an “of/about” boundary, so this guide does not make “of” exclusive in all contexts.
Examples
She is sure of the answer.
“Of” introduces the thing about which she is confident.
They were sure of winning the contract.
The -ing form names the outcome they expected confidently.
I am sure that the file was saved.
A finite clause expresses the full proposition directly.
Further guidance
Construction
Use “sure of” when expressing confidence or certainty about something, including confidence that an outcome will occur.
Style Boundary
Cambridge documents “sure of/about” and specific “sure of” uses; this page records the evidenced construction without claiming that “of” is the only complement available with “sure.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- SURE | English meaning — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct dictionary evidence for “sure of” and the documented “sure of/about” boundary.