The theory of syntactic bootstrapping proposes that children can use syntax to infer the meanings of words. This paper presents experimental evidence that children are also able to use word inflections to infer word reference. Twenty-four- and 30-month-olds were tested in a preferential looking experiment. Children were shown a pair of novel images, one showing a single object, the other a pair of objects, whilst they heard novel words with and without the English plural inflection. Word-image associations were then assessed. Analyses revealed that the older group of children had learnt to associate the words with the appropriate pictures. These results demonstrate that early in the third year, children are readily able to identify whether a spoken word is a singular or plural form, that they have a proper understanding of the significance of plural morphology and that they can deploy this knowledge inferentially to aid the process of word learning--a strategy we call inflectional bootstrapping. (Contains 2 figures and 4 tables.)