Following his move to the University of California, Berkeley, in 1971, this theory eventually evolved into a broader cognitive linguistic theory called Frame Semantics (1976). A commercial event, for instance, crucially involved elements such as a seller, a buyer, some good, and some money. In language, such an event can be expressed in a variety of different ways, e.g. using the verb 'to sell' or the verb 'to buy'. According to frame semantics, meaning is best studied in terms of the mental concepts and participants in the minds of the speaker and addressee.