present in the linguistic or situational context, a generic subject (e.g. 'one') is understood. Representing control Theoretical linguistics posits the existence of the null pronoun PRO as the theoretical basis for the analysis of control structures. The null pronoun PRO is an element that impacts a sentence in a similar manner to how a normal pronoun impacts a sentence, but the null pronoun is inaudible. The null PRO is added to the predicate, where it occupies the position that one would typically associate with an overt subject (if one were present). The following trees illustrate PRO in both constituency-based structures of phrase structure grammars and dependency-based structures of dependency grammars: The constituency-based trees are the a-trees on the left, and the dependency-based trees the b-trees on the right. Certainly aspects of these trees - especially of the constituency trees - can be disputed. In the current context, the trees are intended merely to suggest by way of illustration how control and PRO are conceived of. The indices are a common means of identifying PRO and with its antecedent in the control predicate, and the orange arrows indicate further the control relation. In a sense, the controller assigns its index to PRO, which identifies the argument that is understood as the subject of the subordinate predicate. A (constituency-based) X-bar theoretic tree that is consistent with the standard GB-type analysis is given next: The details of this tree are, again, not so important. What is important is that by positing the existence of the null subject PRO, the theoretical analysis of control constructions gains a useful tool that can help uncover important traits of control constructions. Control vs. raising Control must be distinguished from raising, though the two can be outwardly similar. Control predicates semantically select their arguments, as stated above. Raising predicates, in contrast, do not semantically select (at least) one of their dependents. The contrast is evident with the so-called raising-to-object verbs (=ECM-verbs) such as believe, expect, want, and prove. Compare the following a- and b-sentences: a. Fred asked you to read it. - asked is an object control verb. b. Fred expects you to read it. - expects is a raising-to-object verb. a. Jim forced her to say it. - forced is an object control verb. b. Jim believed her to have said it. - believes is a raising-to-object verb. The control predicates ask and force semantically select their