Explain morphological changes in nouns and verbs from Old English to Middle English.
Old English:
The Noun
The inflection of the Old English noun indicates distinctions of number (singular and plural) and case. The case system is somewhat simpler than that of Latin and some of the other Indo-European languages. There is no ablative, and generally no locative or instrumental case, these having been merged with the dative. In the same way the vocative of direct address is generally identical with the nominative form. Thus the Old English noun has only four cases. As in Indo-European languages generally, the gender of Old English nouns is not dependent upon considerations of sex. The Gender of Old English nouns was not often determined by meaning. Sometimes it was in direct contradiction with the meaning.
Nouns could be of three genders: masculine, feminine or neuter; but these were assigned arbitrarily. Numbers could be either singular or plural, and there were four cases: nominative, accusative, dative, and genitive. In all, there were seven groups of declensions for nouns.
The Verb
Old English distinguished only two simple tenses by inflection, a present and a past, and, except for one word, it had no inflectional forms for the passive as in Latin or Greek. It recognized the indicative, subjunctive, and imperative moods and had the usual two numbers and three persons
The infinitive of verbs ended in -an. In the present tense, all verbs had markers for number and person. The weak past tense added -de, while the strong past tense usually involved a vowel change. Old English also had many more strong verbs than modern English.
Middle English:
The Noun.
Because of the stress shift to the beginning of the word, Middle English lost the case suffixes at the ends of nouns. Phonological erosion also occurred because of this, and some consonants dropped off while some vowels became əand dropped off too. The generalized plural marker became -s, but it still competed with -n.
The strong masculine declension the forms mūð, mūðes, mūðe, mūð in the singular, and mūðas, mūða and mūðum, mūðas in the plural were reduced to three: mūð, mūðes, and mūðe.
We get thus an inflection of the noun identical with that which we have today.
In early Middle English only two methods of indicating the plural remained fairly distinctive: the -s or -es from the strong masculine declension and the -en (as in oxen) from the weak
The weakening of inflections and the confusion and loss of the old gender proceeded
The Verb
Verb infinitives dropped the -an ending, and used "to" before the verb to signify the infinitival form. The third person singular and plural was marked with -(e)th; but the singular also competed with -(e)s from the Northern dialect. More strong (irregular) verbs became weak (regular) as well.
Apart from some leveling of inflections and the weakening of endings in accordance with the general tendency, the principal changes in the verb during the Middle English period were the serious losses suffered by the strong conjugation. This conjugation, although including some of the most important verbs in the language, was relatively small as compared with the large and steadily growing body of weak verbs.
While an occasional verb developed a strong past tense or past participle by analogy with similar strong verbs, new verbs formed from nouns and adjectives or borrowed from other languages were regularly conjugated as weak. Thus the minority position of the strong conjugation was becoming constantly more appreciable. After the Norman Conquest the loss of native words further depleted the ranks of the strong verbs. Those that survived were exposed to the influence of the majority, and many have changed over in the course of time to the weak inflection.