Liquid consonant

In linguistics, a liquid consonant or simply liquid is any of a class of consonants that consists of rhotics and laterals, which are also described as "R-like sounds" and "L-like sounds". Liquids have also been defined as "non-nasal sonorant consonants" (although this definition often includes semivowels as well). The word liquid seems to be a calque of the Ancient Greek word ὑγρός (hygrós 'moist'), initially used by grammarian Dionysius Thrax to describe Greek sonorants.

Liquid consonants are notable for several distinctive properties. They are more prone to be part of consonant clusters and of the syllable nucleus. Acoustically, their third formants are generally non-predictable based on the first two formants. Another important feature is their complex articulation, which makes them a difficult 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/.