Editing Lexical semantics (section)

==== Hale & Keyser 1990 ====
[[File:SyntacticTreeputHaleandKeyser.png|thumb|Hale and Keyser 1990 structure]]
[[Kenneth L. Hale|Kenneth Hale]] and [[Samuel Jay Keyser]] introduced their thesis on lexical argument structure during the early 1990s.<ref name="Hale">{{cite journal|last1=Hale|first1=Kenneth|last2=Keyser|first2=Samuel Jay|title=On Argument Structures and the Lexical expression of syntactic relations|journal=Essays in Linguistics in Honor of Sylvain Bromberger|date=1993}}</ref>
They argue that a predicate's argument structure is represented in the syntax, and that the syntactic representation of the predicate is a lexical projection of its arguments. Thus, the structure of a predicate is strictly a lexical representation, where each phrasal head projects its argument onto a phrasal level within the syntax tree. The selection of this phrasal head is based on Chomsky's Empty Category Principle. This lexical projection of the predicate's argument onto the syntactic structure is the foundation for the Argument Structure Hypothesis.<ref name="Hale" /> This idea coincides with Chomsky's [[Projection Principle]], because it forces a VP to be selected locally and be selected by a Tense Phrase (TP).

Based on the interaction between lexical properties, locality, and the properties of the EPP (where a phrasal head selects another phrasal element locally), Hale and Keyser make the claim that the Specifier position or a complement are the only two semantic relations that project a predicate's argument. In 2003, Hale and Keyser put forward this hypothesis and argued that a lexical unit must have one or the other, Specifier or Complement, but cannot have both.<ref>Paul Bennett, 2003. Review of Ken Hale and Samuel Keyser, ''Prolegomenon to a Theory of Argument Structure.'' Machine Translation. Vol 18. Issue 1</ref>