A study of the definite article 'the' and the indefinite articles 'a' and 'some' in English. H. develops a semantic-pragmatic theory of definite and indefinite reference, and tests it on the grammaticality of numerous article + noun-modifier sequences.On this basis, H. is able to develop a theory on the role of semantics in grammaticality prediction, and more generally to stress the role of semantics in a syntactic theory.