Phonological history of Old English Proto-Germanic phonology and Old English phonology. Proto-Germanic had two allophones each: stops and fricatives . The stops occurred: By West Germanic times, was pronounced as a stop in all positions. The fricative allophones are sometimes indicated in reconstructed forms to make it easier to understand the development of Old English consonants. Old English retained the allophony , which in case of palatalization (see below) became . Later, non-palatalized became word-initially. The allophony was broken when merged with , the voiced allophone of . A number of phonological processes affected Old English in the period before the earliest documentation. The processes
Old English phonology fronting of the open vowel to in certain cases. It also underwent vowel shifts that were not shared with Frisian: smoothing, diphthong height harmonization, and breaking. Diphthong height harmonization and breaking resulted in the unique Old English diphthongs , , , . Palatalization yielded some Modern English word-pairs in which one word has a velar and the other has a palatal or postalveolar. Some of these were inherited from Old English ("drink" and "drench", "day" and "dawn"), while others have an unpalatalized form loaned from Old Norse ( and ). Old English had four major dialect groups: Kentish, West Saxon,