participant involved in the event or action denoted by the predicate. An analogy might help: we can think of a predicate as the script of a play in which there are a number of roles, which correspond to the constituents. Each and every role must be filled for the play to work. In the same way, each predicate specifies the number of arguments needed to complete its argument structure. “One-place predicates” (e.g., intransitive verbs) take just one argument, an external argument that is the subject,