How do children come to be able to discriminate between nouns, adjectives and other grammatical categories? The present study investigated children’s acquisition of the noun category using a syntactic priming method. In the first part of the study, children aged between three and four years took part in a game of ‘snap’ during which they were required to describe the picture on their card to the experimenter who had previously described their card. The prime descriptions of the experimenter either took the form of an adjective-noun clause or a more complex noun-relative clause. The experimenter’s prime descriptions also contained twelve novel nouns. In the second part of the study, adult participants took part in a follow up experiment where they had to play the same snap game as the child participants; this was to provide a comparison between adult and children’s syntactic competence. The results showed that there was a signficant main effect of prime for both children and adults. The effect was stronger for children, which suggests that they are more susceptible to priming because their syntactic categories are more abstract. There was no effect of noun, which indicates that children in particular, have knowledge of an abstract category of noun which they use to process all nouns even if they are unfamiliar with them. These results support the claim that children have an abstract syntactic category of noun by the time they are of pre-school age.