LET SLEEPING DOGS LIE: not to make a bad situation even worse.
TO LET THE CAT OUT OF THE BAG: to talk about somethng you shouldn't.
DON'T COUNT YOUR CHICKENS BEFORE THE EGGS HAVE HATCHED: you should't be happy about something whivh nad not happened yet.
ELVIS HAS LEFT THE BUILDING: a big event has finished.
DON'T CRY OVER SPILT MILK: it's not worth grying from the past.
THAT'S THE BEST THING SINCE SLICED BREAD: something is really good.
IT COSTS AND ARM AND A LEG: it's very expensive.
SPEAK OF THE DEVIL: when you are speaking about someone and suddenly that person appears.
TO SIT ON THE FENCE: not to take decissions.
TO BE THE DEVIL'S ADVOCATE: to present an opposite argument.
