Introduction -- The classification of languages : Genealogical classification of languages -- Typological classification of langugages -- Methods employed in the gathering and analysis of material : The use of written records -- The comparative method -- The method of internal reconstruction -- Study of loss in language; lexicostatistics -- Broadening of language materials; dialect geography -- Models of language -- Change in language : Change in phonological systems -- Change in grammatical systems; analogical change -- Change in semantic systems -- Borrowing: influence of one language or dialect on another -- Conclusion