Image for use in basic articles dealing with parse trees, nodes, branches, X-Bar theory, linguistic theory. S for sentence, the top-level structure in this example. NP for noun phrase. The first (leftmost) NP, a single noun "John", serves as the subject of the sentence. The second one is the object of the sentence. VP for verb phrase, which serves as the predicate. V for verb. In this case, it's a transitive verb hit. D for determiner, in this instance the definite article "the".