13 Common English Idioms and expression Idiom or expression Definition in English Once in a blue moon This is said of something that happens very rarely. This phrase is used to say that two or more people agree on something. This means to do something badly to save money. See eye to eye Cut corners Possible translation and/or interpretation in Spanish “De uvas a peras” “Ver con los mismos ojos”, estar de acuerdo Recortar gastos de mala manera para bajar los costes. “Un ojo de la cara” “Vendar los ojos” An arm and a leg Pull the wool over other people's eyes This is used to describe very expensive things. This means to make someone believe something which is not true / to deceive someone. Feeling a bit under the weather This phrase is used when you are feeling slightly ill. Sentirse medio enfermo Stab someone in the back This means to do or say something bad that is not loyal to someone who trusts you. This means that someone is quick to understand and to react to things. This means to release your emotions, such as anger. This means to report to the authorities about something wrong you know someone is doing. This means to do something that will not get the wanted result. This means to waste time feeling bad about something that has happened and cannot be changed. This means the show is over – go home “Clavar un puñal por la espalda” On the ball Let off steam Blow the whistle Barking up the wrong tree Cry over spilt milk Elvis has just left the building “Tener las pilas puestas” Desahogarse “Dar el chivatazo” Hacer algo que no nos llevará al resultado que queremos. “Llorar por la leche derramada” El espectáculo ha terminado