The consequence of this is that we can now distinguish structurally between the specifier (Determiner) and the complement (“of” PP).
specifier – sister of N' , daughter of NP
complement – sister of N, daughter of N'
That the N-bar level is present also in NPs without complements is shown by:
Mary likes this teacher but not that one.
The argument is based on the assumption that “one” replaces here N’ not N.
That “one” cannot replace N is shown by the ungrammaticality of:
*Mary likes the teacher of English but not [ the [ [ one] [ of French.]]]
NP N’ N
The position of adjuncts
i) I like [ this tall [teacher of E. ]] and she likes [ that small [teacher of E]. ]
NP N’ NP N’
ii) I like [this tall teacher of E] and she likes [that small one]
in ii) “one replaces the head and the complement leaving the adjunct AP intact.
It may seem that adjuncts are outside N’ as in:
Det AdjP N’
iii) I like this tall teacher of English, not that tall teacher of English
iv) I like this tall teacher of English, not that one
iv) shows that “tall teacher of English” can be replaced by one, hence it is an N’ too.
It follows from these examples (i-iv) that the correct structure for “the tall teacher of English” is:
All three modifier functions can now be structurally distinguished
SPECIFIER – daughter of NP, sister of N’
ADJUNCT – daughter of N’, sister of N’
COMPLEMENT – daughter of N’, sister pf N
The PS rules for NP will include:
NP → (Det) N'
N' → AdjP + N'
N' → N (PP)
4) X – bar theory
X-bar theory is a general theory of the internal structure of phrases (applies to all types of phrases in all natural languages, i.e. is a part of a theory of Universal Garmmar)
I.All phrases are “endocentric” – include an obligatory single head word and a number of optional modifiers, The category of the head word determines the category of the whole phrase ( e.g. V is the head of VP, Adj is the head of AdjP etc.)
II.In all phrases there is at least one “intermediate” level of structure between XP and X , the X’ (X-bar) level
III.Specifiers, adjuncts and complementa are distinguished by their position in the structure of the phrase:specifier is a daughter of XP and a sister of X’, adjunct is a daughter of X’ and sister of X’, complement is a daughter of X’ and sister of X (head of the phrase)
According to the X’ theory all phrases conform to the phrase template: (
(X,Q,W,Y,Z are variables standing for word class symbols)
Only the head (X) is always obligatory in XP. It may be its only constituent.
PS rules generating phrase structures are of the general form:
XP → (QP) X’ QP - specifier
X’ → (WP) X’ WP - adjunct
X’ → X’ (YP) YP - adjunct
X’ → X (ZP) ZP – complement
X-bar theory accounts for (among other things) the following facts:
a) complements precede post-head adjuncts (are closer to the head word). This follows from the fact that complements and not adjuncts are sisters to the head word.
b) the number of attributive adjectival phrases in a noun phrase is unlimited (eg - the tall, happy, intelligent black …. boy). This follows from the fact that attributive AdjPs, are adjuncts, and as such are are introduced by a recursive rule: N’ → AdjP + N’.
5. Some X-bar analvses:
A) TP theory of S
Consider the phrase structure of clauses in:
i. Mary thinks [John can drive a car}.
ii. Mary wants [John to be happy].
iii. Mary thinks [John lik(ed/s) motorcycles].
It has been assumed so far that the constituent XP is of the type S(entence). If all constituents are either words or phrases, S should be a phrase too and should conform to the X-bar theory. It should be endocentric, i.e. should have an obligatory head that determines its category/type.
The approach to this problem adopted by many generative grammarians is to propose that the head of S is of a category I or Infl (short from Inflection) (some grammarians use the term T(ense)).
Infl can be realized as either:
a) Modal as in i.
b) infinitive toas in ii.
c) abstract tense morphemes PRESENT or PAST (the choice of tense determines the form of the V-head of the following VP complement (likes vs liked)
Under this approach:
a) all clauses (main and subordinate) are phrases of the type IP
b) the subject of a clause is a specifier in IP(a daughter of IP and a sister of I')