If I want to use an "idiom way" to express I forgot something, which of the following is correct? Thanks much.
1. It must have slipped my mind.
2. It must have slipped off my mind.
Only #1 is correct.
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Thanks very much, Mister Micawber, but could you please explain to me why #2 isn't correct? (Just wanted to learn. Thank you again.)
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The idiom is to slip one's mind. No off; simple as that.
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