fully listening, paying attention
I'm all ears
raining heavily
raining cats and dogs
very jealous
green with envy
very easy
piece of cake
very small quantity, something insignificant
a drop in the ocean
I wish you luck
Break a leg!
wait and be patient
hold your horses
faint
black out
something you enjoy (usually used negatively)
(not) my cup of tea
ill, physically sick
to feel under the weather
very expensive
cost an arm and a leg
reveal a secret
let the cat out of the bag
very rarely
once in a blue moon
be extra nice to someone (usually for selfish reasons)
butter someone up
tryingto do something unrealistic
chasing rainbows
memorize
learn by heart
having a lot of fun
having a whale of a time
catch someone in the act of doing something wrong or illegal
catch red handed
reveal the truth
spill the beans
ignore someone
give someone the cold shoulder
deeply in love
head over heels
become quiet suddenly
clam up
an airplane flight that takes off after midnight
a red eye
calm and relaxed, self-possessed
cool as a cucumber
make a small problem seem big
make a mountain out of a molehill