GREVILLE CORBETT's main research interest is linguistic typology, which investigates types of language subsystems, irrespective of their genetic affiliation, and attempts in this way to constrain the notion of 'possible human language'. Since a good deal of this work deals in implications (any language which has X must have Y), it depends on being able to examine a sample of languages, ideally free from genetic and areal bias. This is becoming increasingly difficult to achieve. Dr. Corbett's specific interests within typology, and topics of his publications, are grammatical categories (particularly gender systems and number systems) and color terms.
Linguists are making increasingly detailed and sophisticated claims about the interrelations of linguistic constructions and of linguistic categories. Research of this type raises the question of the range of data required. Although at first sight the availability (in principle) of 6000 languages might appear wholly adequate, this is not straightforwardly the case. On the one hand, the same features may appear in different languages because they are genetically related; in fact, many languages form large families (Niger-Kordofanian has over 1000 members and Austronesian over 900), which drastically reduces the number of sources of data which are undeniably different. On the other hand, the areal spread of features means that even genetically unrelated languages may share features from a single source. These problems, made more acute by the rapid loss of languages (in Europe as in the other continents), are only just beginning to be appreciated by those who should be most aware of them, for quite selfish reasons, namely linguists. Examples will be given of particularly interesting features which have been found in languages that happen to be endangered, to give some idea of the seriousness of their loss for linguists.