Middle English strong verbs.

The seven classes of OE strong verbs underwent multiple grammatical and phonetic changes.In ME the final syllables of the stems, like all final syllables, were weakened, in Early NE most of them were lost. Thus the OE endings –an., -on, -en were all reduced to ME –en; consequently in Classes 6 and 7, where the infinitive and the participle had the same gradation vowel, these forms fell together. In the ensuing period, the final -n was lost in the infinitive and the past tense plural, but was sometimes preserved in Participle II, probably to distinguish the participle from other forms. Thus, despite phonetic reduction, -n was sometimes retained to show an essential grammatical distinction. In ME and Early NE the root-vowels in the principal forms of all the classes of strong verbs underwent the regular changes of stressed vowels Due to phonetic changes vowel gradation in Early ME was consid¬erably modified for example lengthening of vowels before some consonant sequences. At the same time there was a strong tendency to make the system of forms more regular. The strong verbs were easily influenced by anal¬ogy. It was due to analogy that they lost practically all consonant interchanges in ME and Early NE. The most important change in the system of strong verbs was the reduction in the number of stems from four to three, by removing the distinction between the two past tense stems. The tendency to reduce the number of stems continued in Early NE. At this stage it affected the distinction between the new past tense stem and Participle II. Identical forms of these stems are found not only in the literary texts and private letters but even in books on English grammar. One of the most important events in the history of the strong verbs was their transition into weak. In ME and Early NE many strong verbs began to form their Past and Participle II with the help of the dental suffix instead of vowel gradation. Therefore the number of strong verbs decreased. In OE there were about three hundred strong verbs. Some of them dropped out of use owing to changes in the vocabulary, while most of the remaining verbs became weak. Out of 195 OE strong verbs, pre¬served in the language, only 67 have retained strong forms with root-vowel interchanges roughly corresponding to the OE gradation series.