Slangs, figures of speech and other sentences in different languages or cultures

Slangs, figures of speech and other expressions may cause missunderstandings in different occasions, especially in the communication between people of different cultures or distinct native languages. Please, share those kinds of terms from your native language (or even from another idiom), explaining which is the real meaning of them and how each might be interpreted in other language or culture. Knowledge like this is good to be shared and may avoid mistakes in the communication.