|This text was copied from a written and may need to be wikified to meet Wiki Web standards.|
Please help , especially its section layout, relevant internal links and references
2.7.1. Vowel Change was common in Proto-Indo-European. In many words the vowel varies because of old alternating forms that gave different derivatives.
NOTE. With the creation of zero-grade stems, vocalization appears, as the original radical vowels disappear and new ones are added. That happens, for example, in root bhṛ- [bhr̥], carry, (cognate with English bear), which can be reconstructed from IE languages as bher-, bhor- or bhṛ-. The same can be said of the semivowels [j] and [w] when they are syllable edges, being syllable centres [i] and [u] in zero-grades.
So for example in o-grade domos, house, which gives dómūnos, lord, as Lat. dominus, Skr. dámūnas; but full grade root dem-, which gives demspóts, master, lord, later despot, as Gk. δεσπότης (despótēs), Skr. dampati, Av. dəṇg patōiš, (with fem. demspotnjā).
NOTE. The forms attested in Indo-Iranian (and maybe Greek) come from i-stem potis, probably derived from the original Late PIE form dems-póts, cf. ghósti-pots, guest, as Lat. hospēs, hospitis, O.Russ. gospodь<*-ostьpot-; compare, for an original PIE ending -t in compounds, Lat. sacerdōs < MIE sákrodhots, O.Ind. devastút-, “who praises the gods”, etc. The compound is formed with pot-, lord, husband, and pot-njā, mistress, lady.
2.7.2. Different vocalizations appeared in IE dialects in some phonetic environments, especially between two occlusives in zero-grade, impossible to pronounce without adding a vowel; as e.g. skp-, which evolved as Lat. scabo or Got. skaban.
NOTE. Although the dialectal solutions to such consonantal groups aren’t unitary, we can find some general PIE timbres. As a, i with a following dental (especially in Gk. and BSl.) or u, also considered general, but probably influenced by the context, possibly when in contact with a labial, guttural or labiovelar.
2.7.3. Sometimes different reconstructions might account for some vowel differences; a for o, as *lawō for lowō, wash; a vocalic sonant for a or e plus sonant, as *Sṃos for Samos, summer, or *kṛwos for kerwos, deer, etc.
NOTE. Different reconstructions might be equally valid, depending on the criteria employed. Sometimes different PIE language stages have to be taken into account; as, for root neqt-, night, a common PIH full-grade *neqts is reconstructible, according to Hitt. nekut; however, Late PIE dialects show that an o-grade noun was later generalized; cf. O.Gk. nuks, nuktós, O.Lat. nox, noctis, for an old PIE consonant stem *noqts. The newer i-stem noqtis was the general Late PIE (and later also PII, EIE) form, cf. O.Ind. nakti, Gmc. naxti, Sla. notjь, Bal. nakti.
The phonological reconstruction of Late PIE includes generally the Schwa Indogermanicum, uncertain in sound, which usually stands for an older laryngeal *h2. In North-West IE, PIE reconstructed *ə usually appears as a; as, statis, standing post, from zero-grade *sth2- of root stā- (<steh2-) stay; or patḗr, from older *ph2tér-.
NOTE. Other examples are a-stems in *-ī/-jə, from older *-ih2, and neuter plural in *-ə<*-h2.