In M.A. Arbib (Ed.), The handbook of brain theory and neural networks (2nd ed.). Cambridge, MA: MIT Press.
Upon reflection, most people would agree that the words in a sentence are
not merely arranged like beads on a string. Rather, the words group together
to form coherent building blocks within a sentence. Consider the sentence,
‘The girl liked a boy’. Intuitively, the chunks ‘the girl’ and
‘liked a boy’
constitute the basic components of this sentence (compared to a simple listing
of the individual words or alternative groupings such as ‘the girl liked’ and
‘a boy’). Linguistically, these chunks comprise the two major constituents of
a sentence: a subject noun phrase (NP), ‘the girl’, and a verb phrase (VP),
‘liked a boy’. Such phrasal constituents may contain two types of syntactic
elements: other phrasal constituents (e.g., the NP, ‘a boy’, in the above VP)
or lexical constituents (e.g., the determiner ‘the’ and the noun ‘girl’ in the
NP ‘the girl’). Both types of constituent are typically defined distributionally
using the so-called “replacement test”: If a novel word or phrase has the
same distribution as a word or phrase of a known constituent type—that
is, the former can be replaced by the latter—then they are the same type
of constituent. Thus, the lexical constituents, ‘the’ and ‘a’ both belong to
the lexical category, determiners, because they occur in similar contexts and
therefore can replace each other (e.g., ‘A girl liked the boy’). Likewise, ‘the
girl’ and ‘a boy’ belong to the same phrasal category, NP, because they can
be swapped around as in ‘A boy liked the girl’ (note, however, as we discuss
below, that there may be semantic constraints on constituent replacements;
for example, replacing the animate subject NP, ‘the girl’ with the inanimate
NP, ‘the chair’, yields the semantically anomalous sentence, ‘The chair liked
a boy’).
Click here to
download a PDF version.
Please email suggestions/errors to mhc27@cornell.edu |