The adverb has no morphological properties that may be regarded as specifically adverbial and be used as a criterion to define its morphological status. Absence of inflections is not restricted to adverbs only; degrees of comparison do not cover all the members of this part of speech; only some adverbs are formed by the derivational suffix -ly.

The only grammatical category – the category of degrees of compari­son – are typical of qualitative and of some circumstantial adverbs. Here, a number of adverbs form the degrees of comparison synthetically: early –earlier – earliest, hard – harder – hardest. Meanwhile, there is a number of adverbs that form the degrees of comparison suppletively: well – bet­ter – best, little – less – least, badly – worse – worst, much – more – most, far -farther/further – farthest/furthest.

The degree of increase or decrease of some quality is expressed with other adverbs by means of adding more, most or less, least: The word is less frequently used now, We receive her letters more regularly now.

Some scientists believe that adverbs with more and most do not represent any analytical form but are free word combinations. The arguments to prove this claim are similar to those that are put forward for adjectives. In general, apart from the question of the uses of articles in comparative – superlative collocations, all the problems connected with the degrees of comparison of adjectives retain their force for the adverbial degrees of comparison.