Relier Pairs COMMON IDIOMS IN ENGLISHVersion en ligne A short list of common idioms in English. par kepa olaizola garcia 1 Hit the nail on the head. 2 Piece of cake. 3 Hit the books. 4 Take it easy. 5 When pigs fly. 6 Let the cat out of the bag. 7 Break a leg. 8 Costs an arm and a leg. 9 You can´t judge a book by its cover. 10 Sleep on it. Good luck. To study. Relax You shouldn´t decide upon something based just on outward appearances. Something is very expensive. Something will never happen. Something that is precisely right. Something is very easy. To think. To disclose a secret that was supposed to be kept.