1.) break a leg -- "good luck"
ex. I should break a leg you for your examination tomorrow.

2.) a barrel of monkeys --(very happy)
ex. my friend feel a barrel of monkey when she saw the result.

3.) under the counter -- (secretly)
ex. she give her the wallet under the counter.

4.) snake in a grass -- ( enemy)
ex. don't let him know that because he is a snake in a grass.

5. ) wear a long face -- ( very angry)
ex. I saw her wearing a long face yesterday.