 A theta grid is a schematic representation of the argument structure of a verb with a theta roll to list it. It consists of several components, the base form of the verb, a column for each of the arguments that the verb group requires, and the thematic relations of the argument, its syntactic category, and the argument's index. Each column represents the theta roll assigned by the verb. The thematic relations of an external argument, the subject, are underlined. In the example, John puts the book on the table, we have the di-transitive verb put, that requires three arguments, an agent represented through a noun phrase, in this case John, the theme, the book, also a noun phrase, and the goal on the table, a prepositional phrase. The so-called theta criterion from generative grammar states that each argument is assigned one and only one theta roll, and that each theta roll is assigned to one and only one argument. The theta criterion is satisfied when there's a one-to-one matching between arguments and theta rolls. Violations lead to undramatical sentences. The example John puts the book, lacks a locative, and therefore does not satisfy the theta criterion.