Liquid consonant

This article contains phonetic transcriptions in the International Phonetic Alphabet (IPA). For an introductory guide on IPA symbols, see Help:IPA. For the distinction between [ ], / / and ⟨ ⟩, see IPA § Brackets and transcription delimiters.

Liquids are a class of consonants that consists of rhotics and voiced lateral approximants, sometimes described as "r-like sounds" and "l-like sounds". The word liquid seems to be a calque of the Ancient Greek word ὑγρός (hygrós, transl. moist), initially used by grammarian Dionysius Thrax to describe Greek sonorants.

Liquid consonants are more prone to be part of consonant clusters and of the syllable nucleus. Their third formants are generally non-predictable based on the first two formants. Another important feature is their complex articulation, which makes them a hard consonant class to study with precision and the last consonants to be produced by children during their phonological development. They are also more likely to undergo certain types of phonological changes such as assimilation, dissimilation and metathesis.

Most languages have at least one liquid in their phonemic inventory. English has two, /l/ and /ɹ/.