Listening is a receptive skill, which means receiving language prevails producing it. Listening is the process of interpreting messages, interpreting what is said. Producing messages or texts involves putting them into a form, using individual sounds, syllables, words (which may be linked together), phrases, clauses, sentences and longer stretches of a text. Meaning is added by intonation, and word and sentence stress, too. The listener has to be able to decode a lot of elements to get the message. Listening can be either active or passive. Listening to class discussion, students are expected to respond appropriately, to ask the speakers to repeat what they said, or to clarify what they have said. When listening is more passive, listeners are not expected to respond (e.g. when listening to the news on the radio or a public announcement) or semi-passive listening to a lecture. On the other hand, listening to a lecture can be accompanied by an active approach of listeners who ask for repetition, clarification or providing supportive or contradictory opinions.