Dependency Grammars

In dependency grammars, there are no phrasal levels, nor branch nodes. In dependency grammars, all nodes are terminal. While dependency grammars will yield trees with less nodes than those created under PSGs, it is important to note that Dependency grammars do not reject the idea of constituency. In our dependency example above, boat still dominates the determiner ‘the’, to form the constituent phrase ‘the boat’. However, within dependency grammars, sentences have no VP, and so here, ‘docked the boat’ would not be understood as a constituent. Dependency grammars are very useful for describing languages with a case system that permits free word order. This is due to the fact that PSGs used to describe clauses in free word order languages often result in trees with numerous discontinuities, or crossing of branches, which can obscure constituent relationships.