sure

The word “sure” means certain or confident about something. In plain terms, certain, confident, or reliable — also used casually to mean "yes.".

“Sure” is pronounced sho (/ʃʊɹ/ in IPA).

Here is “sure” used in a sentence: “I'm sure she left already.”

Words with a similar meaning to “sure” include OK and yes.

Depending on how it is used, “sure” can be an adjective and an intj.

The word “sure” comes from Latin. From Old French seur, from Latin securus ("secure, carefree"), from se- ("apart") + cura ("care"). A doublet of secure.

“Sure” is a very common word in modern English, usually learned at around the A1 level.

“Sure” has 3 distinct senses listed in this dictionary. The most common is: certain or confident about something.

The two are very close and often interchangeable. 'Certain' tends to sound firmer and more formal, suggesting there is no doubt at all. 'Sure' is slightly more casual and can express personal confidence as well as fact. You might say 'I'm sure' in conversation and 'it is certain' in careful writing.

'Sure' works in both registers, but it leans informal, especially as a reply meaning 'yes' or 'of course.' In academic or careful writing, 'certain,' 'confident,' or 'convinced' often sound more polished. In everyday speech, 'sure' is perfectly natural and among the most common ways to express confidence.

The opposite is 'unsure,' meaning doubtful or uncertain. Other antonyms include 'uncertain,' 'doubtful,' and 'hesitant.' Someone who is unsure lacks confidence or clear knowledge about something, while a sure person feels confident that they are right or that something will happen as expected.

To be sure of yourself means to feel confident in your own abilities, decisions, or judgment. It describes self-assurance and a lack of hesitation. Used positively it suggests healthy confidence, though in excess it can tip into seeming arrogant or overly certain of being right.