put the finger on

Idioms  

1. Inform on, as in The witness put the finger on the defendant. [Slang; c. 1920] Also see put one's finger on.

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Example Sentences

"It is hard to put the finger on," he replied to an opening question, like a mechanic mystified by a misfiring car engine.

From BBC • Nov. 6, 2022

On removing this some weeks later, he discovered he had put the finger on the wrong way round.

From The Guardian • Jul. 11, 2019

“Don’t put the finger on me, because that’s what you’re doing.”

From New York Times • Jan. 21, 2018

“At any moment he is going to put the finger on you,” she wrote.

From Los Angeles Times • Sep. 18, 2016

These things are often there, but they are not always; and even when they are, there is something else much more important, much more characteristic, but also much harder to put the finger on.

From A History of Nineteenth Century Literature (1780-1895) by Saintsbury, George