Weak and Strong declension
Most adjectives in OE could be declined in two ways: according to the weak and to the strong declension. The formal differences between declensions, as well as their origin, were similar to those of the noun declensions. The strong and weak declensions arose due to the use of several stem-forming suffixes in PG: vocalic a-, ō-, ū- and i- and consonantal n-. Accordingly, there developed sets of endings of the strong declension mainly coinciding with the endings of a-stems of nouns for adjectives in the Masc. and Neut. and of ō-stems – in the Fem., with some differences between long- and short-stemmed adjectives and some remnants of other stems. Some endings in the strong declension of adjectives have no parallels in the noun paradigms; they are similar to the endings of pronouns: -um for Dat. sg., -ne for Acc. sg Masc., [r] in some Fem. and pl endings. The difference between the strong and weak declension of adjectives was not only formal but also semantic. Unlike a noun, an adjective did not belong to a certain type of declension. Most adjectives could be declined in both ways. The choice of the declension was determined by a number of factors: the syntactical function of the adjective, the degree of comparison and the presence of noun determiners. The adjective had a strong form when used predicatively and when used attributively without any determiners. The weak form was employed when the adjective was preceded by a demonstrative pronoun or the Gen. case of personal pronouns. Some adjectives, however, did not conform with these rules: a few adjectives were always declined strong, e.g. eall, maniз, ōþer (NE all, many, other), while several others were always weak: adjectives in the superlative and comparative degrees, ordinal numerals, the adjective ilca ‘same’.
Degrees of comparison
Most OE adjectives distinguished between three degrees of comparison: positive, comparative and superlative. The regular means used to form the comparative and the superlative from the positive were the suffixes –ra and –est/-ost. Sometimes suffixation was accompanied by an interchange of the root-vowel.
The vocabulary and word-building means in Old English.
The OE vocabulary was almost purely Germanic; except for a small number of borrowings, it consisted of native words inherited from PG or formed from native roots and affixes.
Native words
Native OE words can be subdivided into a number of etymological layers from different historical periods. The three main layers in the native OE words are:
a) common IE words;
b) common Germanic words;
c) specifically OE words.
Words belonging to the common IE layer constitute the oldest part of the OE vocabulary. Among these words we find names of some natural phenomena, plants and animals, agricultural terms, names of parts of the human body, terms of kinship, etc.; this layer includes personal and demonstrative pronouns and most numerals. Verbs belonging to this layer denote the basic activities of man; adjectives indicate the most essential qualities.
The common Germanic layer includes words which are shared by most Germanic languages, but do not occur outside the group. Being specifically Germanic, these words constitute an important distinctive mark of the Germanic languages at the lexical level. This layer is certainly smaller than the layer of common IE words. Semantically these words are connected with nature, with the sea and everyday life.
The third etymological layer of native words can be defined as specifically OE, that is words which do not occur in other Germanic or non-Germanic languages. These words are few, if we include here only the words whose roots have not been found outside English: OE clipian ‘call’, OE brid (NE bird) and several others. However, they are far more numerous if we include in this layer OE compounds and derived words formed from Germanic roots in England, e.g. OE wīfman or wimman (NE woman) consists of two roots which occurred as separate words in other OG languages, but formed a compound only in OE.