Spanish Idioms

The following are more common Spanish idioms that will help improve your ability to converse in Spanish and improve your fluency.
It is raining cats and dogs
Llueve a cántaros
(literal: It is raining pitchers)
Birds of a feather flock together
Dime con quien andas y te diré quien eres
(literal: Tell me with whom you walk and I'll tell you who you are)
You can't teach an old dog new tricks
El loro viejo no aprende a hablar
(literal: The old parrot doesn't learn to talk)
A friend in need is a friend indeed
En el peligro se conoce el amigo
(literal: In danger the friend is met)
You reap what you sow
Se cosecha lo que se siembra
(literal: What you sow, you will harvest)
It is the early bird that gets the worm
A quien madruga, Dios le ayuda
(literal: God helps he who wakes up early)
A bird in the hand is worth two in the bush
Más vale un pájaro en mano que cien volando
(literal: One bird in hand is worth more than a hundred flying)
You make me crazy
Me vuelves loco
(literal: You make me crazy)
Out of sight, out of mind
Ojos que no ven, corazón que no siente
(literal: Eyes that do not see, heart that does not feel)
You can't please everyone
Nunca llueve a gusto de todos
(literal: It never rains to everyones liking)
The best things in life are free
Lo que no cuesta dinero siempre es bueno
(literal: What does not cost money is always good)
We all make mistakes
Él que tiene boca se equivoca
(literal: He who has a mouth makes mistakes)
You never know what you have until it's gone
Nadie sabe lo que vale el agua hasta que falta
(literal: Nobody knows how much water is worth until it's missing)
If you keep your mouth shut, you wont put your foot in it
En bocas cerradas no entran moscas
(literal: In closed mouths, flies don't enter)
Necessity is the mother of invention
La necesidad agudiza el ingenio
(literal: Necessity sharpens ingenuity)
Look before you leap
Antes que te cases, mira lo que haces
(literal: Before you marry, look what you do)
Is the coast clear?
¿Hay moros en la costa?
(literal: Are there Moors on the coast?)
Brain is better than brawn
Más vale maña que fuerza
(literal: Skill is worth more than power)
Think before you speak
Antes de hablar, pensar
(literal: Before speaking, think)