Cost an arm and leg
Costar un ojo de la cara
He bought a new MP3 player. It cost an arm and leg.
Be out of pocket
Estar sin un duro
I spent a lot of money and now I am out of pocket
Be in the red
Estar en números rojos
I usually finish the month in the red
Make ends meet
Llegar a fin de mes
If you don't have a job, its hard to make ends meet.
Pass with flying colours
Aprobar coon sobresaliente
I'm very happy, I've passed my English test with flying colours.
Hit the books
Estudiar duro
I have to hit the books if I want to pass my exams.
Crack a book
Abrir el libro para estudiar
I passed eventhough I didn't crack a book
Eager Beaver
Que se esfuerza mucho
He is really an eager beaver and deserves to pass
I flunked because I didn't study
Learn By heart/Learn by rote
Aprender de memoria/de pe a pa
I have to learn that subject by rote
Play hooky
Hacer pellas
I dislike students who play hooky
Cut class/ditch class
Saltarse la clase
I cut class because I was sick
Take the roll
Pasar lista
The teacher takes the roll everyday
Ace a text
Clavar un examen
I aced the text, I'm very happy
Blow a test
Fastidiar un examen (suspender)
I blew the test because I didn't study enough.