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Have and Of

Commonly Confused Words


Have and Of

Have is an auxiliary verb. Of is a preposition. Use have (or its contracted form 've) with could, must, should, would, may, and might.


  • Jed could have tried harder to help us.

  • Jed said, "I wish I would've tried harder."

  • Some of us must have been watching the game when the burglars broke into the house.

  • "If the Mets would have given him two more runs per game, Seaver would have won 20 games by the end of August. But that was one of those would've, could've, should've scenarios." (Josh Rosengren, Hammerin' Hank, George Almighty and the Say Hey Kid: The Year That Changed Baseball Forever, 2008)

  • "Not one of us could have planned the fly, not one of us could have constructed him; and no one would have considered it wise to try, except under an assumed name." (Mark Twain, "Thoughts of God")

Usage Notes:

  • "Mr. Wood, my English teacher, is always telling us that 'there's no such thing as must of, should of, could of, it's must have, should have, could have.' Mr. Wood says stuff like, 'The day you all get that simple little fact into your tiny little heads is the day I can retire a happy man.' Well, this is all very well and good, but he doesn't need to be moaning on to me about it."
    (Hayley Long, Lottie Biggs Is (Not) Mad. Macmillan, 2009)

  • "When we speak, we slur these phrases so that they all sound as if they end in of, but in fact all of them end in have. Their correct forms are may have, might have, must have, should have, would have, and could have."
    (Susan Thurman, The Only Grammar Book You'll Ever Need. F+W Media, 2003)


(a) One _____ us made a mistake.

(b) It must _____ been you.

Answers to Practice Exercises

Glossary of Usage: Index of Commonly Confused Words

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