1. "Break a leg" - used to wish someone good luck, especially before a performance or presentation.
2. "Bite the bullet" - to face a difficult or unpleasant situation with courage and determination.
3. "Cost an arm and a leg" - to be very expensive.
4. "Piece of cake" - something that is very easy or simple to do.
5. "Hit the nail on the head" - to accurately identify or describe something.
6. "Kill two birds with one stone" - to accomplish two things at the same time.
7. "Let the cat out of the bag" - to reveal a secret or surprise.
8. "Once in a blue moon" - something that happens very rarely.
9. "Raining cats and dogs" - used to describe heavy rainfall.
10. "Under the weather" - feeling unwell or sick.