gemination

Gemination, or consonant lengthening, is a phonological phenomenon in which a consonant is pronounced for a longer duration than a singleton. In languages with contrastive gemination, the length of a consonant distinguishes word meaning, producing minimal pairs; in others, consonant length is not phonemic but is determined by phonotactic constraints or morphology.

Acoustically, a geminate consonant is longer in time and often more intense than a singleton, though the precise profile varies by place and manner of articulation. Stops, fricatives, nasals, and laterals can be geminated. The length usually affects the adjacent vowels, and in some languages the timing of voicing may differ across geminated segments. This feature interacts with syllable structure and stress patterns.

Distribution and typology: Gemination is systematic in many Afro-Asiatic languages (for example Arabic and Hebrew) and in several Indo-European languages (such as Italian and Finnish) and Turkic languages (such as Turkish). In Japanese, gemination is signaled orthographically by a sokuon and affects the onset of the following consonant. In English and many other Germanic languages, consonant length is not phonemic, though allophonic or prosodic length variations occur.

Orthography and history: Many writing systems indicate gemination by doubling the consonant letter (for instance Italian, Finnish, and Turkish). Others use diacritics or special symbols, such as the Arabic shadda to mark a geminated consonant. Gemination often arises from historical assimilation or morphophonemic processes and can be preserved or simplified in different languages over time.