BMN ANGD A2 Linguistic Theory
Lecture 6: Generalisation
1
Generality and Explanation
To set the scene for this lecture I would like to compare the first transformational theory of
Chomsky (1957) with that of the Extended Standard theory of the 1970s. Recall that in the 57
theory there was a set of phrase structure rules which generated a core set of ‘kernel’
sentences and then a set of transformations which were responsible for generating all other
sentence types. This essentially put the rules of the grammatical system in a one to one
correspondence with the linguistic phenomena that the grammar was attempting to account
for: a core set of rules corresponded to a core set of sentences and extra rules corresponded to
extra sentences:
(1)
Grammar
Language
PS rules
kernel
sentences
T1
T2
T3
T4
…
sentence type 1
sentence type 2
sentence type 3
sentence type 4
…
Essentially, the grammatical system merely reflects linguistic phenomena and is therefore just
as complex as the object it addresses. It is clear that in such a situation the grammar does no
more than describe the data. Moreover, when we consider that the situation above describes
just a single language and we would have to have a similar model for every single existent
and indeed possible human language, there is very little understanding to be gained
concerning the nature of possible human languages nor accounting for how linguistic systems
arise in the individual (i.e. how language acquisition is possible!). Essentially the only limits
imposed on the system are empirical in nature: the set of observed sentence types limit the
grammatical rules needed to account for them. In principle then, the grammar could contain
any conceivable rules and a child faced with the task of learning a grammatical system could
entertain any conceivable system. In other words, this kind of view of the linguistic system
does not help us to understand the possibility of language acquisition as we are left with the
question that if a learner can hypothesise any conceivable system, how are they able to
narrow their hypotheses down to the correct one?
Now compare this to the Extended Standard Theory, in which the phrase structure rules are
not restricted to forming a subset of sentences, but are relevant to all sentences of the
language, albeit at a deeper level of analysis, and there is a restricted set of transformations
which are not associate with just one sentence type, but with a whole set of sentence types:
Mark Newson
(2)
Grammar
Language
PS Rules
constraints
T1
T2
T3
Note that the structure of the grammar does not simply reflect that of the language and
moreover, while the language may involve fairly complex phenomena, the grammar remains
relatively simple. In this way the grammar is more than just a translation of the linguistic
phenomena into descriptive rules, but goes some way to improving our understanding of the
phenomena itself.
The other advantage of this kind of grammatical system is that as the rules themselves are not
specifically related to language particular structures, but to something far more general, the
rules themselves may have greater application to other languages and as such they represent
something far more indicative of the basic nature of human languages as a whole. Obviously
languages differ from one another, but from this perspective, given that each rule is
associated with a wide range of phenomena, it might be that small alterations in the grammar
result in wide ranging differences in observable languages. If what has to be learned is
limited to such small differences in the grammatical system, the whole question of how
language can be acquired is more easily answered. The grammatical system itself imposes
huge restrictions on the notion of a possible human grammar and as such the task of language
learning is much simplified.
What the above discussion illustrates is the relationship between the generalisation of
linguistic rules and the explanatory content of the theory within which those rules are stated.
In a nutshell, the more general the grammatical system, the more explanatory the theory.
In this lecture, we will discuss how the developments that took place in the 1970s along the
lines sketched above culminated at the beginning of the 1980s in a theory which attained an
unprecedented level or explanation. We will concentrate on two grammatical areas, the
phrase structure rules and the transformation component.
2
Phrase Structure and X-bar theory
Phrase Structure rules were Chomsky’s formalisation of the Structuralist idea of Immediate
Constituent Analysis. From the start they were fairly descriptive devices capable of
modelling any possibility for constituent structure. So if an NP contained a determiner
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Generalisation
followed by a noun, this was just as easy to model as if an NP were to contain a verb
followed by a preposition:
(3)
a
b
NP → Det N
NP → V P
The fact that only one of these possibilities is actual in any language is then, as far as the
basic theory of phrase structure based on such notions is concerned, pure accident. In other
words, given that this observation is clearly no accident, the theory cannot explain the facts.
The structuralists had noted that some phrases are replaceable by one of its constituents, or in
other words that a part of the phrase can function as the whole. So, to take a famous example
from Bloomfield (1933):
(4)
a
b
poor John ran away
John ran away
Here the phrase poor John is replaced by John and hence the single noun can function as the
whole phrase indicating the noun’s centrality within the phrase. The term head was given to
such central elements, and phrases which had heads were called endocentric. Not all
linguistic constituents were endocentric, however. The most obvious unit that cannot be
replaced by one of its constituent being a sentence:
(5)
a
b
c
poor John ran away
poor John
ran away
While (5a) has the status of a sentence, neither (5b) nor (5c) do. Nor does any other
constituent of (5) for that matter. Hence it was proposed that sentences are exocentric, lacking
a head.
It is clear however that a phrase structure rule of the form X → Y Z cannot capture the notion
head and hence endocentric and exocentric structures are given the same treatment:
(6)
NP → Adj N
S → NP VP
While we can say that the noun is the head of the noun phrase in the first rule, there is
nothing in this rule that informs us of this apart from the apparently descriptive accident that
the phrase is labelled with the same category symbol as the noun. Given that in principle (3b)
is a possible phrase structure rule and there is no head of this NP we can see that phrase
structure rules are not capable of capturing the notion of endocentricity nor the connected
notion of a head.
After more than ten year of working with phrase structure rules, Chomsky (1970) proposed a
revision to the phrase structure component of the grammar, which has since become known
as X-bar theory. Chomsky’s proposal was not particularly detailed and was virtually tacked
on to the end of a paper about the difference between derived nominals and gerunds, which
need not concern us here. The main point of the proposal was to capture certain similarities
between certain elements and their dependants. Starting with verbs, which had traditionally
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Mark Newson
been subcategorised in terms of their following dependants (transitive verbs having objects,
prepositional verbs having prepositional complements, etc.), Chomsky observed that nouns
and adjectives, even those not derived from verbs, can also be subcategorised along similar
lines:
(7)
a
b
c
treat [with penicillin]
treatment [with penicillin]
treatable [with penicillin]
book [about linguistics]
fond [of chocolate]
The phrase structure grammar would seem to contain the following rules therefore:
(8)
VP → V Comp
NP → N Comp
AP → A Comp
where ‘Comp’ stands for the dependent phrase or ‘complement’. Clearly there is a
generalisation to be had here which is entirely missed by stating these three separate rules. In
each case the phrase is endocentric and the head precedes the complement. Chomsky’s
proposal was to capture this generalisation by using a category variable X to represent the
head and the category of the phrase it heads:
(9)
X' → X YP
The symbol X' (pronounced X bar) represents a phrase whose category is determined by the
head and thus this system is able to capture the notion of an endocentric constituent.
Chomsky also saw the need to include material which preceded the head, such a determiners,
auxiliary verbs and degree adverbs:
(10)
a
b
c
the book
have gone
so tall
He termed these elements specifiers and proposed the following rule:
(11)
X" → Spec X'
The category X" (pronounced X double bar) represents the full phrase and hence phrases
generated by these rules have the following structure:
(12)
X"
Spec
X'
X
YP
Although Chomsky did not mention prepositions in the (1970) paper, it is clear that these can
also be included in the set of things that X in the rules (9) and (11) can range over. Soon after,
then, X was taken to range over N, V, A and P.
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Generalisation
In the 1970 paper, it was never really stated what the status of the rules in (9) and (11) were
supposed to be taken as, but it seems that in the period that followed they were generally
assumed to be a kind of template for possible phrase structure rules. For example, this was
how they were taken in Jackendoff (1977), which was one of the major work at the time on
the subject of X-bar syntax. The reason for this was the fact that there still seemed to be
phenomena which were idiosyncratic to certain phrases and as X-bar rules do not distinguish
between phrases of different types, specific rules for NPs, VPs, etc. were still needed.
For example, it is well known that while verbs and prepositions can take NP complements,
nouns and adjectives cannot:
(13)
a
b
c
d
tell him
to him
* picture him
* capable it
picture of him
capable of it
This cannot be a lexically determined thing as is not something specific to particular lexical
items, but is something that is true of a whole category. The only place that such
generalisations can be captured therefore is in the grammar and the phrase structure
component seems to be the best place for them. Hence there was a need for rules such as the
following:
(14)
V' → V NP
P' → P NP
N' → N PP
A' → A PP
Given that these rules conform to the pattern set down by the X-bar rule in (9) they were
considered valid under the view that the role played by (9) was to licence possible phrase
structure rules which were of a more specific nature. In a sense, the relationship between the
X-bar rules and phrase structure rules is similar to the relationship between transformations
and constraints on transformations.
Although this position is more restricted an general than that which held prior to 1970, it still
isn’t entirely satisfactory as there are still construction specific rules which are therefore of a
descriptive nature. There are no explanations in the rules in (14), for example, for why nouns
and adjectives in English cannot have NP complements.
However there were a number of developments which enabled steps to be made towards a
greater generalisation of the system and ultimately allowing rules such as (14) to be
eliminated from the grammar. Recall the Case Filter from last week. This is a filter that
controls the surface distribution of NPs, forcing them to occupy Case positions. The data in
(13) indicate that the complement position of nouns and adjectives is not a Case position and
under this assumption, that nouns and adjectives cannot take NPs in their surface complement
positions is accounted for independently and does not have to be stipulated in terms of
specific phrase structure rules. Stowell (1981) proposed that all phenomena that necessitate
category specific phrase structure rules can be accounted for by independent principles of the
grammar and hence the phrase structure part of the grammar can be eliminated entirely,
leaving only the general X-bar rules to deal with the basic structural properties of a language.
The theory which emerges looks like the following:
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Mark Newson
(15)
X-bar Theory
Lexicon
D-structure
Transformations
Constraints
S-structure
Case Theory
However, at this stage of the theory there still remain at least two structures that are
exocentric and hence which stand outside of X-bar theory altogether, S and S, and a large
number of elements, such as determiners, auxiliaries and complementisers which are not
associated with phrases and so which are also not part of the X-bar system.
It is interesting to note that at this point X-bar theory was seen as a theory of the structure of
certain linguistic elements, nouns, verbs, adjectives and prepositions, which were referred to
traditionally as the major categories, but are also called the lexical or thematic categories,
whereas the non-X-bar elements were what are traditionally termed minor categories, though
these days are more often called functional categories. Clearly the traditional names ‘major’
and ‘minor’ reflects the attitude that the thematic elements are somehow more important and
this attitude seemed to prevail in X-bar theory too. It is quite obvious however that this view
is guided by the fact that the thematic elements carry the larger part of the semantics whereas
the functional elements have only a secondary role to play in terms of meaning. While this
was the kind of thing that tended to influence traditional grammars, which tended to be
meaning centred, it should not have been a factor in modern grammar which has, since the
structuralists, maintained that syntax and semantics are separate (if related). It wasn’t until
the early part of the 1980s theoretical interest eventually turned to the functional categories
and more importance began to be placed on these elements. For example Borer (1984)
proposed that most important linguistic differences can be traced to differences in properties
of functional categories and hence it is these that define a particular language and these
properties that children have to learn when acquiring language.
The first changes reflecting this newly acquired interest in functional elements came with the
analysis of the clause. Recall, this was analysed as an exocentric structure as in the following:
(16)
S
COMP
S
NP INFL VP
COMP represents the position of the complementiser (not to be confused with Comp, the
complement position in an X-bar structure) and INFL (for ‘inflection’) represents the position
of the tense element (including modal auxiliaries and the infinitive marker to). Also recall
6
Generalisation
that S (pronounced ‘S bar’) was an independent notion from X-bar, indicating that this
element is clausal in nature, but different from S. The possibility that the clause was not
exocentric was considered in the 1970s and there seemed to be two possibilities for the
choice of the head. Jackendoff (1977) championed the idea that the verb was the head of the
clause, making S categorially a VP. The other view was that the inflection was the head of
the clause, though it was not until the 1980s that this was taken seriously and the following
representation appeared (in Stowell (1981), for example):
(17)
S
IP

NP I VP
NP
I'
I
VP
This suggestion actually kills two birds with one stone as not only does it provide an X-bar
analysis for the S node, but it also considers the inflection to be a category capable of being a
head. It also makes the head of the clause a functional element which fits nicely with the
growing interest in the syntactic role of functional categories.
From this move it seemed to follow naturally that S should also fall into an X-bar type
analysis and the obvious move was to consider the complementiser as its head, again bringing
another functional element into the realms of X-bar theory:
(18)
S
C
CP

S
(wh)
C'
C
IP
Recall that the wh-element, fronted in interrogatives, was not assumed to occupy the COMP
position, but be adjoined to it. The CP analysis confirms the independence of the
complementiser and the wh-position, but here the wh-element is moved to the specifier
position.
The final functional element to fall to an X-bar analysis was the determiner. Fukui (1986) and
Abney (1987) both provided an analysis of what had traditionally been taken to be a phrase
headed by the noun and argued that the real head was the determiner:
(19)
NP
Det
the N
DP
N'
D'
PP
picture of Mary

D
NP
the
N'
N
PP
picture of Mary
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Mark Newson
Although this is not the place to try to justify these analyses, it is worth pointing out that even
from structuralist criteria taking the determiner as the head of the ‘NP’ has its justification.
Recall Bloomfield’s notion of a head being a part of a phrase that can function as the whole.
In Bloomfield’s example poor John, John was identified as the head, but suppose we
consider another example: that dog. Clearly dog cannot function as the whole phrase here,
but that can:
(20)
a
b
c
he patted that dog
* he patted dog
he patted that
From a structuralist point of view, this provided contradictory evidence for the head of this
kind of phrase and hence already more sophisticated argumentation is necessary to conclude
whether the head should be taken to be the noun or the determiner. Abney provides such
sophisticated argumentation and concludes in favour of the determiner.
To conclude this section, we have seen how a process of generalisation has been directing the
development of the part of the grammar which attends to basic structural issues. Starting with
phrase structure rules, which were construction specific and rather descriptive in nature, a
series of developments have led to the position in which there are just two phrase structure
rules:
(21)
XP → Spec X'
X' → X YP
These are clearly not construction specific and to the extent that they account for all aspects
of phrase structure can be seen to attain high levels of explanatory adequacy. For example,
these rules can be assumed to underlie the phrase structures of all human languages and
hence pose no particular problem for learning: they can be assumed to be universal and hence
part of the innate linguistic system. Languages may differ, for example in terms of whether
the head precedes or follows its complement, but the general rule that the head and the
complement form a constituent (X') is universal. Thus the amount of learning involved in this
aspect of language is minimal and can be done on the basis of exposure to quite simple data.
3
Transformations
We have seen how transformations started off as structure specific rules in the 1960s and as a
result of the addition of constraints became far more general. Indeed, by the end of the 1970s
it was generally accepted that there were two main transformations, one for moving NPs into
subject positions and one for moving wh-elements into COMP. Besides these there were a
number of other transformations which seemed to be of a stylistic nature and were generally
optional, so perhaps belonging to an entirely different part of the grammar.
The two major movements, NP-movement and Wh-movement, could not be further reduced
as it appeared they were subject to different conditions: NP-movement being restricted by the
Tensed S Condition and the Specified Subject Condition and Wh-movement being restricted
by the Crossover Conditions (see lecture 4). Perhaps this was not an impossible situation, but
it still raised questions that could only be solved in a stipulatory manner, such as why there
are these two transformations and why they have the particular properties that they do.
8
Generalisation
Once again, developments in other parts of the grammar proved helpful to overcome these
problems. Specifically it was the development of trace theory that allowed the final step in
the generalisation of the transformational component. We will go into the details more fully
next week, but the observation was that the traces involved in structures formed by various
movement phenomena had different properties. Consider a straightforward case of NPmovement, for example:
(22)
a
b
c
John1 seemed [ t1 to be rich]
* John1 seemed [ t1 is rich]
* John1 seemed [ Mary to like t1]
We see that an NP is allowed to move out of the subject position of a non-finite clause, but
not out of a finite clause (violating the Tensed S Condition) or out of an object position
(violating the Specified Subject Condition). This pattern is repeated in phenomena
concerning the referential properties of certain pronouns:
(23)
a
b
c
John1 believes [himself1 to be smart]
* John1 believes [himself1 is smart]
* John1 believes [Mary to like himself1]
In (23), we use indexes to indicate the referent of the pronoun. What we see is that a reflexive
pronoun in the subject position of a non-finite clause can refer to an element in the
dominating clause, but not if it is in a finite clause or in object position. These data can be
handled if we assume that the traces in (22) are subject to the same grammatical principles as
the pronouns in (23), or in other words, these traces and pronouns form a coherent class of
elements, known as anaphors. With this assumption, then, these restrictions can be factored
out from the movement process altogether and whatever the more general conditions that
determine the properties of anaphors, accounting for the Tensed S Condition and Specified
Subject Condition, are not to be taken as constraints on particular movements all.
A similar move can account for Crossover phenomena too. Recall that a wh-element is not
allowed to move over the top of a coreferential element:
(24)
a
b
who1 t1 said [he1 likes Mary]
* who1 did he1 say [t1 likes Mary]
In this case we cannot liken the behaviour of the trace to that of a reflexive pronoun, as
replacing the trace with such a pronoun gives an ungrammatical sentence in both cases:
(25)
a
b
* himself1 said [he1 likes Mary]
* he1 said [himself1 likes Mary]
However, if we replace the trace with a full referential NP we get the required result, so in
this case it seems that the trace behaves like a referential expression:
(26)
a
b
John1 said [he1 likes Mary]
* he1 said [John1 likes Mary]
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Mark Newson
Again, factoring these conditions out of the movement process altogether and imposing them
as restrictions on types of traces, we no longer need to claim that there is a type of movement
which is restricted by a specific constraint.
The part of the grammar which was developed to account for the referential properties of
elements such as reflective and personal pronouns and referential expressions such as names
was called Binding Theory and its conditions act like Filters applying at S-structure, defining
possible referential interpretations for the relevant elements. Seeing traces as having
referential properties and hence being subject to the principles of Binding Theory was one of
the major developments which allowed apparently structure specific restrictions to be
factored out of transformations entirely.
Because of these developments, the transformational component was ultimately reduced to a
single transformation. This transformation did not have to stipulate what element had to
move, as this was determined by independent considerations such as the Case filter – forcing
NPs to move out of Caseless positions, for example. Nor did it have to stipulate where the
element had to move to – the Case Filter required Caseless NPs to move to Case positions. In
fact all that was required of the transformation component was the statement that things can
move and all the specific details of particular movements, which had previously been
encoded in the transformations themselves, was factored out to other independently
motivated parts of the grammar. The transformation required was then:
(27)
Move 
Move anything anywhere
Obviously this is the most general transformation there could possibly be, something that
might easily be part of an innate system and given that in most languages there is some
indication that some elements undergo movement processes it is a universal aspect of
languages too. Of course, there are differences in what moves where in languages: not all
languages move wh-elements to the front of the clause in interrogatives, for example. But as
these facts are not specific to the transformational component, but to other aspects of the
grammar, they do not need to be encoded in the transformation rule itself.
The grammar we end up with is as follows:
10
Generalisation
(28)
X-bar Theory
Lexicon
D-structure
Move 
S-structure
Constraints
Case Theory
Binding Theory
4
Conclusion
In the grammatical system represented in (28) we can start to see the beginnings of the theory
that developed in the 1980s, known as Government and Binding theory. One of the most
obvious features of this system is its modular nature: there are independent grammatical
modules, each of which addresses specific grammatical phenomena, such as X-bar theory
addressing basic structural issues and Binding Theory addressing referential phenomena, and
each of which contains a small number of general grammatical principles. The complexity of
the linguistic system does not stem from the complexity of the grammatical rules themselves,
but from the complex way these rules interact with each other. For example, Case theory
imposes a simple restriction on S-structure, that all NPs/DPs must be in Case positions, and
this in turn places requirements on movement, forcing elements to move out of Caseless
positions into positions where they can get Case. The movement component itself, however,
simply permits movements of any kind, but only those which serve to satisfy the Case Filter
will give rise to grammatical structures.
Given that the structure of the grammar can be taken to be universal, and the simple
principles of the grammatical modules are also general enough to be considered universal,
this model goes a long way to solving the question of how language acquisition is possible.
What has to be learned are the lexical elements and their properties, which given that this
amounts to a finite body of knowledge, poses no particular logical problem, and also some
fairly superficial differences in how the principles themselves are to be applied, such as
whether heads precede complements. Because of the complex interaction between the simple
and general modules of the grammar, however, simple changes in one module might result in
dramatic differences in terms of what structures are grammatical between languages. So
while languages may look to differ one from another in vast and complex ways, the actual
difference between the grammatical systems, which is after all what has to be acquired, may
be relatively minor. Such was the optimistic hope of 1980s grammar, at least. We shall see
that while some of this optimism was justified, ultimately Government and Binding theory
raised as many questions as it solved, however.
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Mark Newson
References
Abney, Stephen Paul 1987 ‘The English Noun Phrase in its Sentential Aspect’, PhD.
dissertation, MIT, Cambridge, Mass.
Bloomfield, Leonard 1933 Language, Rinehart and Winston, New York.
Borer, Hagit 1984 Parametric Syntax, Foris, Dordrecht.
Chomsky, Noam 1970 ‘Remarks on Nominalisation’, in Jacobs, R. and P.S. Rosenbaum
(eds.) Readings in English Transformational Grammar, Ginn and Co., Waltham,
Mass.
Fukui, N 1986 ‘A Theory of Category Projection and its Applications’, Ph.D. dissertation,
MIT.
Jackendoff, Raymond 1977 X-bar Syntax, MIT Press, Cambridge, Mass.
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