heyfre

Forms with /ɛː/ continue Late Old English hēafru, which develops from a syncopated hēahfru with simplification of the resulting consonant cluster /xfr/. In these forms, the first-syllable vowel /æ͜ɑː/ retained its length, regularly developing to /ɛː/ because the medial cluster /fr/ was identified as the onset of the second syllable (i.e. /ˈxæ͜ɑː.fre/). Forms with /ɛ/ and /a/ come in part from forms where the cluster was split between the two syllables, resulting in regular shortening of the initial-syllable vowel (i.e. /ˈxæ͜ɑf.re/), but as we will see, they also continue Old English trisyllabic hēahfore.

In trisyllabic forms of this word (hē̆ahfore, hē̆hfore), the first-syllabic vowel was regularly shortened due to trisyllabic shortening; the remaining forms with /ɛ/, /a/ develop when /x/ was lost before it could cause the diphthongisation ("breaking") of the preceding vowel, while those with /æi̯/ are the result of this breaking. In forms with /kf/, /x/ was subject to fortition instead of being lost (pace Liberman; compare sixt (“(thou) seest”), sikth (“(he) sees”)); forms with /fk/ are further developments of these forms due to metathesis.