put (your) finger on (something)

to discover the exact reason why a situation is the way it is, especially when something is wrong.

I know there's something wrong, but I can't put my finger on exactly what it is. (often negative)

I think you've just put your finger on the biggest problem facing the Conservative party in this election.

• turn up the heat
• turn your back on
• turn your back on someone
• turn your back on something
• turn your hand to
• turn your hand to something
• turn your nose up
• turn your nose up at
• turn your nose up at something
• twiddle thumbs
• twiddle your thumbs
• twilight zone
• twist arm
• twist around little finger
• twist around your little finger
• twist in the wind
• twist of the knife
• twist round little finger
• twist round your little finger
• twist someone around little finger
• twist someone around your little finger
• twist someone round little finger
• twist someone round your little finger
• twist someone's arm
• twist the knife