Sure! Here are some common idioms and expressions:

1. “Break a leg” - This is a way to wish someone good luck, especially before a performance or presentation.

2. “Bite the bullet” - This means to face a difficult or unpleasant situation with courage and determination.

3. “Cost an arm and a leg” - This means something is very expensive.

4. “Piece of cake” - This means something is very easy or simple.

5. “Hit the nail on the head” - This means to accurately identify or describe something.

6. “Kill two birds with one stone” - This means to accomplish two things at the same time.

7. “Let the cat out of the bag” - This means to reveal a secret or confidential information.

8. “Once in a blue moon” - This means something happens very rarely.

9. “The ball is in your court” - This means it is someone’s turn to take action or make a decision.

10. “Under the weather” - This means to feel sick or unwell.

These are just a few examples, but there are many more idioms and expressions in the English language. Learning and using idioms can make your language more colorful and expressive.