Table 8

The root-vowel interchanges in long, eald, ʒlæd go back to different sources. The variation [a~ æ] is a purely phonetic phenomenon; retraction of [æ] before the back vowel in the suffix -ost is not peculiar to the adjective. The interchange in long and eald is of an entirely different nature: the narrowed or fronted root-vowel is regularly employed as a marker of the comparative and the superlative degrees, together with the suffixes. The mutation of the root-vowel was caused by i-umlaut in Early OE. At that stage the suffixes were either -ira, -ist or -ora, -ost. In the forms with -i- the root vowel was fronted and/or made narrower; later -i- was lost or weakened to -e- – but the mutated root-vowel survived as an additional formal marker of the comparative and superlative degrees.

Some adjectives had parallel sets of forms: with and without a vow­el interchange. These sets could arise if the adjective had originally employed both kinds of suffixes; or else the noun-mutated vowel was restored on the analogy of the positive degree arid other adjectives without sound interchanges.

The adjective ʒōd had suppletive forms. Suppletion was a very old way of building the degrees of comparison (it can be illustrated by the forms of adjectives in other IE languages: G gut, besser, beste, Fr mal, pire, R хороший, лучше).