Government and Binding Theory/Logical Form

In the book, we have discussed syntax in great detail, without touching on semantics. However, there is an interface between semantics and syntax, so this isn't something we can simply discard - without semantics, syntax would be of no use. Thus far, we have discussed two forms, the D-structure and the S-structure. It may be tempting to think that one of these is the semantic interface, but we can see that this is not the case. Scope ambiguity, for example, often occurs in English. Refer to the following example:

(1) Everybody heard something.

In (1), there is no movement between D- and S-structures, so the argument applies to both. Let H be a predicate '____ heard ____', T be a predicate '____ is a thing', and P be a predicate '____ is a human'. There are two possible interpretations:

(2a) ∃x(Tx&∀y(Hy→Hyx)) (2b) ∀x(Hx→∃y(Ty&Hxy))

If neither D-structure nor S-structure is the syntax-semantics interface, then what?

Quantifier
Linguists have proposed a third syntactic layer of representation that serves as the interface between the syntax and semantics. This is the Logical Form (LF). Quantifiers are moved to the front in the logical form. Refer to the following example (let i be a constant meaning whoever I is, and let E be a predicate '____ ate ____'):

(3a) S-structure: I ate everything. (3b) LF: Everything I ate. (3c) ∀x(Tx→Eix) (3d) For every x, where x is a thing, I ate x.

The S-structure (3a) is transformed into the LF (3b), which in turn is interpreted by our conceptual-intentional system as the semantic representation (3c).

Moreover, the S-structure is transformed into another form, the Phonetic Form (PF), which is interpreted by our sensorimotor system so that we can read out the word in our minds. This led to the T-model of transformation below: