keep someone guessing

present singular third person keeps someone guessing · participle present keeping someone guessing · participle past kept someone guessing · past kept someone guessing

1. To act in such a way that others do not fully understand what one has done or do not know what to expect next.

   She could not even dimly understand Helen's merry protestation that it was fun to make people wonder and keep them guessing.

   1924, Martha Dickinson Bianchi, “Chapter 7”, in The Life and Letters of Emily Dickinson

   2 more examples

   But I do like to delight people with intense, focused, essential flavors, to give them the pure joy of fresh asparagus in springtime. I'm looking to amuse them and maybe (occasionally) keep them guessing: "How did he get that asparagus to taste so... asparagussy?"

   2006, Geoffrey Zakarian, Geoffrey Zakarian's Town/Country: 150 Recipes for Life Around the Table, New York, N.Y.: Clarkson Potter/Publishers, →ISBN, page 8

   Being slightly off one’s trolley Uppermost in my list of top four teaching behaviours is being ever-so-slightly crazy ... to keep students guessing whether or not I have lost my marbles, and being not quite so predictable.

   2006, Mike Ollerton, Getting the Buggers to Add Up, Continuum International Publishing Group, →ISBN, page 164