There is not much to be said about the English adjective from the morphological point of view. As is well known, it has neither number, nor case, nor gender distinctions. Some adjectives have, however, degrees of comparison, which make part of the morphological system of a language. Thus, the English adjective differs materially not only from such highly inflected languages as Russian, Latin, and German, where the adjectives have a rather complicated system of forms, but even from Modern French, which has preserved number and gender distinctions to the present day (cf. masculine singular grand, masculine plural grands, feminine singular grande, feminine plural grandes 'large').
By what signs do we, then, recognise an adjective as such in Modern English? In most cases this can be done only by taking into account semantic and syntactical phenomena. But in some cases, that is, for certain adjectives, derivative suffixes are significant, too. Among these are the suffix -less (as in useless), the suffix -like (as in ghostlike), and a few others. Occasionally, however, though a suffix often appears in adjectives, it cannot be taken as a certain proof of the word being an adjective, because the suffix may also make part of a word belonging to another part of speech. Thus, the suffix -ful would seem to be typically adjectival, as is its antonym -less. In fact we find the suffix -ful in adjectives often enough, as in beautiful, useful, purposeful, meaningful, etc. But alongside of these we also find spoonful, mouthful, handful, etc., which are nouns.
On the whole, the number of adjectives which can be recognised as such by their suffix seems to be insignificant as compared with the mass of English adjectives.
The only morphological problem concerning adjectives is, then, that of degrees of comparison.
