piece of cake -- something that is easy
You really went the extra mile by doing the extra credit.
go the extra mile --- doing more than you have to do
I'm green with envy; Marco got the award for class president, not me.
green with envy-- to be jealous/envious
It's raining cats and dogs out there; make sure you have an umbrella before you leave for school.
raining cats and dogs out there -- raining very heavily
Edward was over the moon about wining the trivia contest.
over the moon -- extremely happy
Mayra and Ximena are two peas a pod.
two peas in a pod--- two people who are very similar/get along well
You're going to sink or swim in the class. If you do the extra credit, you'll be fine. But if you don't study or try, you're going to fail.
sink or swim --- failing or succeeding
You just got offered a full ride scholarship to college, this is a golden opportunity for you!
golden opportunity-- great opportunity
I'll run a marathon when pigs fly... I hate running.
when pigs fly -- something you'll never do
My friends were able to apologize to each other; now that old argument is just water under the bridge.
water under the bridge -- something that happened in the past and you no longer need to worry about it
I'm walking on eggshells around my mom; she's so mad that I lied about my grades.
walking on eggshells -- nervous because someone is upset with you
Ryan was teasing Amy about her new haircut and she told Ryan, "take a hike!".
take a hike-- go away
black sheep-- someone who feels like an outsider/disgrace to their family
I felt like a fish out of water at the speech and debate club; I hate public speaking!
a fish out of water -- feeling very uncomfortable in a situation
Lola always goes with the flow; even if plans change she doesn't get upset.
go with the flow -- someone who is accepting of things/changes
go bananas -- get very excited, wild
I'm going to touch base with you before our presentation so we can double check who is saying what.
touch base-- briefly meeting with someone
Raul was feeling blue after he was late to the airport and missed his flight to see his family.
feeling blue-- feeling sad
You can kill two birds with one stone; you can go to the party and talk to your crush.
kill two birds with one stone-- do two things at once
smart cookie --- someone who is smart/intelligent
Time to get the ball rolling on our presentation, it's due in three days.
get the ball rolling -- start something
Yolanda was seeing red after her friend lied to her and didn't invite her to a birthday party.
seeing red-- very angry
Dude, clam down! You've got ants in your pants. Everything is going to be ok with your presentation. You'll get an A on it for sure.
ants in your pants -- being very nervous
We're going to test the waters and see if pushing lunch 30 minutes later works for the students.
test the waters-- experiment, see if something works