IDIOM

My grandfather is very absent-minded and often forgets his key. 

all ears: eager to listen to someone
(todo oídos)

Okay, I'm all ears, please tell me about the party. 

all of a sudden: suddenly, without advance warning (repentinamente)

All of a sudden it became cloudy and began to rain. 

beat around the bush: speak indirectly
or evasively (dar vueltas para hacer algo)

Stop beating around the bush and give us your final decision.

behind the times: old fashioned (anticuado)

My aunt is a little behind the times.

blow one's own horn: praise oneself (fanfarronear, hacer alarde)

He is always blowing his own horn and is very annoying at times.

brand new: absolutely new (flamante)

He was finally able to buy a brand-new car.

catch one's eye: attract one's attention (llamar la atención)

I tried to catch her eye but she didn`t notice me.

catch (someone) red-handed: find someone in the middle of doing something wrong (atrapar a alguien con las manos
en la masa)

The policeman caught the boy red-handed when he was stealing the candy. 

change horses in midstream: make new plans or choose a new leader in the middle of an important activity (cambiar de caballo en la mitad del río)

They decided to change horses in midstream and that is probably why they lost the election.

change (one's) mind: change one`s decision (cambiar de opinión)

He changed his mind and said that he would not go to the movie tonight. 

come across: find something or meet someone by chance (encontrarse repentinamente con algo o alguien)

I came across an interesting story in the newspaper the other day. 

come into fashion: become fashionable (ponerse de moda)

She says that although bell-bottom pants have come into fashion again she will never wear them. 

crocodile tears: a show of sorrow that
is not really felt (lágrimas de cocodrilo)

He said that he was very sorry but his tears were just crocodile tears. 

cry over spilt milk: cry or complain about something that has already happened (llorar sobre leche derramada)

Don't cry over spilt milk. You can never change the past.

die out: die or disappear slowly until all gone (desaparecer, extinguirse)

Dinosaurs died out millions of years ago. 

doll up: dress in fancy clothes (emperifollarse, vestirse de moda)

She was all dolled up for the party at the downtown hotel

do without: manage without something (arreglárselas sin algo)

If there is no sugar, we'll have to do without. 

dressed to the nines (teeth): dressed elegantly (elegantemente vestido, "hasta los dientes")

The stars were all dressed to the nines (teeth) during the Academy Awards ceremony. 

dress up: put on one's best clothes (vestirse formalmente)

He decided to dress up for dinner at the restaurant.