The aim of this article is to help to clarify the highly complicated and vexed issue of the use of different linguistic varieties in spoken Czech. The term 'varieties' refers both to distinctive language types and to hybrid forms of expression, which are determined by the social characteristics of the speaker and by the context of a particular utterance or series of remarks. The article is intended primarily for non-native speakers, to whom deviations from the standard, somewhat literary-sounding form of Czech, known as spisovna ceStina, can pose quite considerable difficulties. It is accepted implicitly that all scholars who wish to appreciate something of the richness and diversity of spoken Czech must at the very least learn to recognize the characteristic morphological, phonological and lexical differences between spisovna ceStina and the more informal styles of speech widely used for the purpose of everyday communication. The question of the co-existence of different linguistic varieties is not of paramount importance to the majority of native speakers. Most adult Czechs have little need to reflect consciously on the way they express themselves since they have learnt through extensive practical experience to adopt language styles which they (rightly or wrongly) consider to be appropriate in given circumstances. The same, however, cannot be said of Czech children or of foreigners who can sometimes feel ill-at-ease in unfamilar settings and ill-equipped linguistically to deal with the demands made of them in new social surroundings. All teachers of Czech (whether teaching Czech to native speakers or as a foreign language) are aware of the difficulties posed by the co-occurrence and inter-relationship of different styles of speech. Yet there is a considerable divergence of opinion amongst scholars with respect to the status, functions and definitions of the various non-standard forms of the spoken language. Whilst all scholars recognize that spisovna cestina is inherently more stable than any other form of Czech, they remain divided over the precise role and characteristics of the different types of language used in everyday conversation. In all languages non-literary forms of expression are prone to fluctuation and inevitably change much more quickly than the codified norms. Not only is there a great deal of variability within the verbal repertoire of a given community, but even individual speakers can show considerable inconsistency in their use of language, in particular with respect to lexical items. Czechs frequently combine