h₂ew-
“to perceive, to hear”Perceive, hear, be aware
Reconstructed as "to perceive, to be aware," with principal reflexes in Latin audīre ("to hear," whence audience, obey), Greek aísthēsis ("perception," whence aesthetics), and Sanskrit ávati ("favours, helps"). The Germanic evidence is uncertain.
Discussion
The root *h₂ew- is reconstructed with the meaning "to perceive, to be aware" and is treated in Pokorny (IEW 78) and Rix (LIV²). The initial laryngeal *h₂ produces the characteristic a-colouring of the root vowel in daughter languages. The root is less widely attested than many of the core PIE verbal roots, and some of the proposed cognates — particularly in Germanic — remain contested. The principal reflexes in Latin and Greek are, however, well established and phonologically regular.
Latin audīre ("to hear"), generally derived from *h₂ew-is-dʰh₁- or a related formation with a compound structure, is the most productive continuation. The derivative vocabulary is extensive: audientia ("a hearing," whence audience), audītōrium, audītus ("the sense of hearing"), and the compounds obaudīre ("to listen toward, to obey," whence English obey through Old French obeir) and inaudītus ("unheard of"). The semantic extension from hearing to obedience — preserved in obey — reflects a social pragmatics in which "to hear" entails "to heed," a development paralleled in other language families. Ernout and Meillet discuss the morphological formation of audīre and its relationship to the root.
Greek aísthēsis (αἴσθησις, "perception, sensation") has been connected to *h₂ew- through a formation *h₂ew-is-dʰh₁-, "a putting into awareness," though the morphological analysis is debated. Beekes (s.v. αἰσθάνομαι) discusses the competing etymological proposals. If the connection holds, the Greek derivative underlies the modern philosophical vocabulary of aesthetics (coined by Baumgarten in 1735), anaesthesia ("absence of sensation"), and synaesthesia ("co-perception"). The semantic trajectory from bodily perception to philosophical reflection on beauty and art is a post-classical development, but the root itself encodes the broader perceptual sense.
Sanskrit ávas ("favour, satisfaction, aid") and the related verb ávati ("helps, favours, protects") show a semantic shift from perception to the positive disposition that arises from attentiveness: to perceive is to notice, to notice is to favour. This development, while less transparent than the Latin and Greek reflexes, is accepted by Mayrhofer (s.v. ávati) as compatible with the root. The Avestan cognate avah- ("help, support") confirms the Indo-Iranian form.
The Germanic evidence is uncertain. The connection of Old English ēare ("ear") to this root, sometimes proposed, is not generally accepted; the standard etymology of "ear" derives it from *h₂ows- (a distinct root). Old High German ōra and Gothic ausō likewise belong to *h₂ows- rather than *h₂ew-. The root *h₂ew- thus remains primarily a Latin, Greek, and Indo-Iranian item, with its status in other branches unresolved. Watkins (s.v. au-) catalogues the derivatives but notes the limited distribution.
Laryngeal Analysis
Initial h₂ (a-colouring).
Ablaut
Full grade *h₂ew-, zero grade *h₂u-.