If α directly or indirectly θ-marks β, we say that α "selects" β. A verb, for example, selects its complement and also selects its subject if it participates in assigning a θ-role to the subject. Note again that if α selects β, then β is either a position or a category "C" such that "C" or its trace occupies the position selected by α.
- Chomsky (1993), Pag. 38