tailieunhanh - Constituent Structure - Part 24

Constituent Structure - Part 24 | 8o PHRASE STRUCTURE GRAMMARS AND X-BAR The -relations can be calculated by comparing each of these monostrings to the terminal string example from Lasnik 2000 24 a he left he VP b he left he V c he left NP left d he left S therefore left VP therefore left V therefore he NP therefore he left S Note that there are number of relationships not expressed in this notation. For example it does not assert that V VP nor VP V 6 nor does it assert that NP VP S. The RPM simply does not contain this information. Despite what you might construe from the tree representations of such sentences the only constituency relationships are between terminals and the nodes that dominate The sentence is otherwise ordered by the precedence relations expressed in the monostrings. Trees although helpful to the student and linguist are not actually an accurate representation of the P-marker as it was originally conceived by Chomsky and later extended by Lasnik and Kupin. Indeed Lasnik and Kupin 1977 and Kupin 1978 suggest we can do away with trees and the PSG component entirely . the sentences are not derived by a PSG but rather are declaratively stated with the restriction that the RPM express all the relevant -relations and be ordered by dominance and precedence . As we will see when we look at Bare Phrase Structure in Chapter 8 a derivational version of this set theoretic idea returns to generative grammar in much more recent versions of the theory. Regular grammars context-free and context sensitive grammars There are a variety of types of phrase structure grammar. They vary in their power to make accurate empirical predictions and in the kinds of 6 This means that VP V and left are actually unordered with respect to one another in terms of immediate dominance. This is perhaps part of the motivation for abandoning non-branching structures from the theory of Bare Phrase Structure discussed in Ch. 8. 7 More precisely simple dominance is an important relation in this theory but .