ABSTRACT
This chapter outlines Tree Pruning Hypothesis (TPH) linguistic theoretical framework, the empirical evidence for it, problems inherent in the theory. It examines the question of how to interpret the tree pruning metaphor and how faithfully we should or should not adhere to linguistic theory. Friedmann and Grodzinsky and subsequently, Friedmann had the advantage of working in Hebrew and Palestinian Arabic, languages with rich inflectional systems in which agreement and tense marking affixes are clearly identifiable. While, in principle, the performance of neurologically impaired patients may modify well established linguistic theories, however, to do so, the evidence and the argumentation have to be convincing. It does not seem that Friedmann dealt convincingly with the evidence of variability, of conflicting evidence from the languages with different organization of the syntactic tree, or evidence that overrides the interdependency of the Inflection Phrase (IP) and Complementizer Phrase (CP) layers.
