A Dictionary of Linguistics and Phonetics David Crystal

378 postvocalic
postvocalic (adj.) In phonetics and phonology, a term describing a sound
which follows a vowel. For example, /t/ is postvocalic in the word cat.
‘Postvocalic r’ refers to the use of an r quality after vowels in certain accents
(e.g. in Scotland and most parts of the USA). There is a contrast with prevocalic,
referring to a sound which precedes a vowel – /k/ in the word cat, for example.
Some consonants are restricted to one position or the other: in English
syllables, /h/ occurs only prevocalically, as in hot, and /º/ only postvocalically,
as in sing.
potential lexicon
see potential word
potential pause A term often used in grammar to refer to a defining property
of the word, seen as a grammatical unit. The criterion states that, in normal
speech, pauses are not introduced within the structure of the word but are
always possible (and often present) at word boundaries.
potential word In linguistics, a term for any word which can be generated
using the word-formation rules of a language, even though it has not yet been
attested. In English, the attested lexicon includes revision from revise, but not
devision (from devise), which thus remains part of the potential lexicon. Similarly,
slock is a potential word, on phonological grounds, but fnock is not.
poverty of the stimulus The name given to an argument in language acquisition,
as identified by Noam Chomsky, that the samples of language available to
a child are insufficient to explain the adult’s knowledge of language (the ‘finalstate
grammar’); also referred to as ‘Plato’s problem’ or ‘the logical problem
of language acquisition’. The innateness hypothesis is invoked to resolve the
problem. See also Chomskyan, evidence, innateness.
power (n.) (1) A term used in the formal evaluation of grammars, and particularly
found in discussion of generative theories; also called capacity.
Basically, grammar A would be said to be more powerful than grammar B if it
can generate more languages (sentences, etc.) than B. In this sense, a contextfree
grammar is more powerful than a finite-state grammar. It is important,
however, that a grammar should not become too powerful, in the sense that
it generates sentences which are ungrammatical, structural descriptions which
are intuitively implausible, or a characterization of natural language that is
too broad (e.g. including features of non-language systems). formal constraints
therefore have to be built into grammatical models to restrict the power of
grammars in specific ways, and much current discussion is focused on this
subject. A further distinction is often introduced, between weak and strong generative
power within a grammar. In the notion of ‘weak’ generative power,
a grammar (or rule, or set of rules, etc.) is said to be more powerful than
another if it generates more grammatical sentences. In the notion of ‘strong’
generative power, a grammar is said to be more powerful if it assigns to these
sentences a set of structural descriptions which more satisfactorily shows
their relationships.
(2) See loudness.