apple expressions

How do you like them apples?!
What do you think about that? (sarcastic)

An apple a day keeps the doctor away.
Apples are so nutritious that if you eat one every day, you won’t need to go to the doctor.

Don't upset the apple cart!
Don’t ruin something.

You're the apple of my eye!
Someone’s favorite person.

One rotten apple spoils the barrel.
A bad person negatively influences the people s/he comes into contact with.

As American as apple pie.
Typically American.

It's like comparing apples and oranges
Comparing things that are completely different.