In casual speech, when you agree with somebody’s statement, you may say “for sure.” Your date says ”That was outstanding tiramisu.” and you, wanting to show how in tune you are, reply “For sure!” You can also use the phrase to mean “for certain,” as in “I couldn’t tell for sure that the bench was wet until I sat on it.”

But people often substitute this phrase when they should use plain old “sure,” as in “I couldn’t be for sure.” That should be “I couldn’t be sure.”

List of errors