Eckhard Bick - VISL

Generative Grammar, introduced and advocated by Noam Chomsky in the fifties 92 as
Generative-Transformational Grammar, comes in many flavours. It is alive and well
today in the shape of - for example - Government and Binding Theory (GB),
Generalised Phrase Structure Grammar (GPSG) or Head Driven Phrase Structure
Grammar (HPSG). One of the main - and most revolutionary - ideas of early Phrase
Structure Grammar (PSG) was to express syntactic function as constituent structure.
Thus, a subject would be implicitly defined as that noun phrase (NP) which is left after
removing a sentence’s other main constituent, the verb phrase (VP) 93 . A pure PSG
would take word class information from a lexicon of full-forms, ignoring inflexion and
semantic information. The grammar as such would then consist of rewriting rules that
allow substitution of lower-level symbol sequences for higher-level symbol sequences
(so-called “productions”). Symbols can be terminals (words or word classes) or nonterminals
(complex units of words and/or symbols), and providing for a start symbol S
(typically a sentence), we arrive at the following complete “grammar” for the PSG
meta-language:
1. T terminal vocabulary set (e.g. words and parts of speech)
2. N non-terminal vocabulary set (e.g. noun phrase, verb phrase)
3. P set of productions a -> b (e.g. noun phrase -> determiner noun)
4. S start symbol, a member of N
A miniature grammar, capable of generating the sentence ‘The cat eats a mouse’, would
consist of a lexicon of terminals (‘the’ det, 'a' det, ‘cat’ n, ‘mouse’ n, ‘eats’ v), nonterminals
(NP = noun phrase, VP = verb phrase), and the following three productions:
S -> NP VP
VP -> v NP
NP -> det n
Agreement is hard to express by word class alone (plural nouns and 3.person singular
verbs, for example, would have to be separate word classes), but can be incorporated in
the form of Prolog style arguments, as in Definite Clause Grammar (DCG), for instance:
S -> NP(number) VP(number)
VP(number) -> V(number) NP(number2)
NP(number) -> det(number) n(number)
92 Chomsky’s Syntactic Structures was published in 1957.
93 One can say, that this idea is further pursued in Categorical Grammar where all word classes and phrase classes are
defined in terms of constituent categories, with only two basic categories, s (sentence) and t (referent, i.e. “noun”).
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