Analyzing Syntactic Structure

For analyzing the structure of a sentence we will use constituent analysis, a hierarchical model introduced by Chomsky [1]. In this framework, sentences are modeled in the form of a parse tree (see Figure 1), where leaves are lexical items, or terminals, and internal nodes are constituent labels. The constituent labels form grammatical types from the lexical items, and lexical items form the sentence. For example, the first level of the tree in Figure 1 tells us that the analyzed sentence S is made out of a noun phrase NP and a verb phrase VP. To see this more clearly, let us introduce the following, more compact, notation: [[Police] NP [put barricades around Upson] V P ] S