not have a clue

Idioms  

1. Have no idea or inkling about something, as in Jane doesn't have a clue as to why John won't call her, or Do you know what's wrong with the boiler?—No, I haven't a clue. This usage was first recorded in 1928.

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Example Sentences

You might not have a clue it exists - let alone that you might need to train it.

From BBC

He said he did not have "a clue" what he had done on the night of 27 September as it was a month before, but added he "didn't do much" and would either have been at home or with a friend or his girlfriend, who he referred to as his "bird".

From BBC

Asked about that finding, Welby said: "You can believe it or not, I did not have a clue."

From BBC

I really do not have a clue how this one will go, so I suppose the sensible thing for me to go for is a draw,

From BBC

It'd be silly to go through life and not have a clue about that guy, 'cause he's just one of those people.

From Salon