In construction grammar (2 ), the 'slots' encoded by a particular verb which determine what participant types can be combined with the verb. This follows from the assumption that the semantics of any verb are relativized to a semantic frame. The semantic frame is, in turn, held to determine the participants that can be associated with the verb. For example, the verb buy might be associated with the participant roles buyer, seller and goods, while the verb sing might be associated with the participant roles singer and song.