Angluin’s pattern languages that use pattern strings as language descriptors,have motivated researchers in formal language theory to introduce and investigate grammarsbased on patterns. Both theoretical as well as application oriented properties of these gram-mars have been studied. On the other hand pure grammars in line with the early works ofThue have been proposed and studied for their properties. Here we introduce a new kind oflanguage generative device, called a pure pattern grammar,linking the notions of patternand pure grammars. Two modes of derivation in such a pattern grammar, called as syn-chronized and non-synchronized modes, are introduced. Theresultant families of languagesare compared for their generative power with certain other well-known families of languages.Certain closure properties and descriptional complexity results are also obtained
