EVOLUTION OF CONSONANTS IN MIDDLE ENGLISH AND EARLY NEW ENGLISH
§ 402. English consonants were on the whole Ear more stable than vowe1s. A large number of consonants have probably remained unchanged through all historical periods. Thus we can assume that the sonorants [m, n, l], the plosives [p, b, t, d] and also [k, g] in most positions have not been subjected to any noticeable changes. They are found in many words descending from OE though their correlations in the system of phonemes have altered to a varying degree.
The most important developments in the history of English consonants were the growth of new sets of sounds, — affricates and sibilants, — and the new phonological treatment of fricatives. Both changes added a number of consonant phonemes to the system. On the other hand, some consonants were lost or vocalised, which affected both the consonant and the vowel system. Like vowel changes, consonant changes can be shown as occurring in the transition period from Written OE to Late ME that is in Early ME, and in the transition from ME to the language of the 18th c, that is in the Early NE period.