Previous research has shown that children go through a
stage in which
they know that the number words each refer to a distinct
numerosity, yet
do not know WHICH numerosity each number word picks
out (Wynn, 1992). How do children attain this level of
knowledge? We explore the
possibility that particular properties of how number words
are used within sentences inform children of the semantic
class to which they belong. An analysis of transcripts of
the spontaneous speech of three
one- and two-year-old children and their parents (from the CHILDES
database; MacWhinney & Snow, 1990) suggests that the
relevant cues are available as input in parents' speech
to children, and that children
generally honour these properties of number words in their
own speech. Implications of this proposal for word learning
more generally are discussed.