Government and Binding Theory/DP Hypothesis

Although we have so far treated the determiner and possessor as the possible specifiers of the noun phrase, there are several problems with this:
 * Determiners are functional, but possessors are lexical.
 * Determiners are words, but possessors are phrases.
 * The two are not in complementary distribution in some languages, like Hungarian. Since the two can co-exist, they cannot both fill up the specifier slot.
 * There is some evidence suggesting that the determiner is a head. For example, incorporation is a process that whereby two heads are joined to form a complex head. In French, the prepositions à and de can join with the determiners le and les through incorporation:

(1a) *Je suis à le parc → Je suis au parc (1b) *Je demande à les étudiants → Je demande aux étudiants (1c) *la plupart de les étudiants → la plupart des étudiants

Since the determiner seems to be a head, the determiner phrase has been suggested as its maximal projection.

The Determiner Phrase
The determiner phrase suggested by Abney has an X-bar structure like any other phrase:



This gives us a 'bare-bones' structure of the DP. Let's flesh it out by filling up the specifier slots of the DP and the NP.

Phrases with possessives
Let's consider the case of DPs with possessives. Under the DP hypothesis, the possessive phrase is assumed to be the specifier of the DP. This leads to an important question, though: What sits in the head position of the DP?



For now, we will insert here an empty pos determiner:



Phrases with post-determiners
The DP hypothesis also provides a home for post-determiners, like many and several. They have determiner-like properties, but are not exactly determiners, and they have adjunct-like properties, but aren't exactly adjuncts, as we can see here:

(2a) The many people (2b) *The many several people

(2a) shows that they aren't in complementary distribution with determiners, but (2b) shows that they aren't adjuncts. The specifier position of the NP can now accommodate these determiner-like entities: