Distinctive feature

In linguistics, a distinctive feature is the most basic unit of phonological structure that may be analyzed in phonological theory.

Distinctive features are grouped into categories according to the natural classes of segments they describe: major class features, laryngeal features, manner features, and place features. These feature categories in turn are further specified on the basis of the phonetic properties of the segments in question. Since the inception of the phonological analysis of distinctive features in the 1950s, features traditionally have been specified by assigning them binary values to signify that the segment being described by the feature either possesses that phonetic property or it does not. Therefore, a positive value, [+], denotes the presence of a feature, while a negative value, [?], indicates its absence. However, in recent developments to the theory of distinctive features, phonologists have proposed the existence of single-valued features. These features, called univalent or privative features, can only describe the classes of segments that are said to possess those features, and not the classes that are without them.