Adverbs are words which modify verbs, adjectives, other adverbs, nouns, numerals or quantifiers, and also whole phrases or clauses, in order to indicate various relationships (time, manner, place, quantity, etc.) or to qualify what is being said in some other way. In this section we are concerned with adverbs which stand in a close morphological relationship with adjectives; in other words, we shall be dealing only with adverbs which are formed from the corresponding adjectives according to certain rules or patterns. We shall not, therefore, examine here the many adverbs of place, time, manner, quantity, etc. which are not derived directly from declined adjectives. (For types of adverb and their uses see Part III, Sections 3.1 and 3.2.)
There are two main adverbial endings for the forms derived from adjectives: -α and -ως. Some adjectives can use either ending (but with a possible distinction of register or stylistic level and sometimes with a different stress), but for most adjective types there is only one way to form the corresponding adverb. We shall consider in turn the adverbs ending in -α (Section 4.1), those ending in -ως (Section 4.2), and then some irregular forms (Section 4.3). Adverbs are indeclinable, but like adjectives they have degrees of comparison (see Section 4.4).