Idioms
"Break a leg!" I said to him before the show.
Good luck!
He was as quiet as a mouse when he left the room.
Very quite, not making much noise
I am a night owl.
Like staying up late
He was as busy as a bee.
Very busy, Simile
She really let the cat out of the bag when she revealed the secret plans.
Told the secret
He slept like a log.
Very still, didn't move
He has a heart of gold.
He is a walking encyclopedia.
Very smart, knowledgable, metaphor
The exam was challenging for some, but for others it was a piece of cake.
Easy
My hands are as cold as ice.
Freezing, very cold
The classroom was a zoo.
The classroom was crazy, loud
My friend looked out the window and said, "it's raining cats and dogs!"
It's raining heavy, Idiom
I was over the moon when my best friend and I both made the team.
Excited
The ice cream was as solid as a rock.
Very hard
She is such a chicken.
She is scared
Watching the movie was like watching grass grow
Very boring, Metaphor