binary feature
in linguistics, a feature of the phonemic system of a language that has two mutually exclusive aspects, such as voiced–unvoiced (in English) or aspirated–unaspirated (in Hindi). Such features have a critical contrastive function, working rather like an on–off switch to distinguish one phoneme from another; in English, for instance, the otherwise very similar sounds [b] and [p] are recognized as distinct phonemes because the former is voiced and the latter unvoiced. Binary opposition of this kind is a key concept in the structuralist interpretation of language and in the wider structuralist movement generally (see structuralism). See also minimal pair. [first described by Russian linguist Roman Jakobson (1896–1982)]