Page 384 - DENG504_LINGUISTICS

Linguistics

Notes That is why it is needed to impose contextual restrictions upon the operation of the rules. A grammar
that includes one or more context-sensitive rules is called a context-sensitive phrase structure
Grammar. These rules can be formulated in various ways. For instance, the following :
Z + X + W—>Z + Y + W or X—> Y/Z (—) —> W

that is, X is to be written as Y in the environment of Z to the left and W to the right. This system of
rules is required mainly to include the phenomenon of concord or agreement in grammar. For example
:
V+s/ in the context NP sing + ...
Verb-V +φ in the context NP plur + ....
Context-free phrase structure grammars can be defined as a sub-class of context-sensitive grammars.
Any set of sentences that can be generated by a context sensitive grammar, but the converse is not
true. Context-sensitive grammars are more powerful and precise than context-free grammars.
Limitations of Phrase Structure Grammars

(a) A phrase Structure Grammar is essentially a grammar of segmentation and categorization; it is
a taxonomic model—a Grammar of lists, an inventory of elements. Although it is very strong in
the matter of giving structural description of the language, yet it is deficient in generative capacity.
It is incapable of accounting for all the intuitions of native speakers. It fails to disambiguate all
the ambiguities and understand all the synonymities. “A phrase structure grammar accounts
for intra-sentence constituent relations like-active-passive, declarative-interrogative, affirmative-
interrogative, etc.”
(b) A PS grammar cannot adjunct, delete and permute. The processes that pose problems to PS
grammar are :
• ambiguities
• synonymities
• permutations
• discontinuous constituents (e.g. particles)
• remote relationships (e.g. those of cases)
• concord phenomena
• co-ordination
(c) Despite its rules of inference, binarity and irreflexivity etc., a PS grammar runs into difficulties
in describing syntactic structures of Questions, Negatives, Passives, Relatives, etc. easily. It
fails to grasp the deep meaning. It cannot discover the crucial notions, nor can it prevent the
assignment of false, ungrammatical structure.
PS rules are incapable-except by having recourse to very arbitrary solution—of accounting for
the multiplicity of relations existing either between elements in the same sentence, or between
different sentences. For example :
(1) The police diverted the traffic.
(2) The traffic was diverted by the police.
(3) The traffic was diverted by a country road.
The PS rules will fail to show the relationship that connects (1) to (2). In sentence (2) “by the
police” will be shown as prepositional phrase consisting of a preposition, a determiner and

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