Adverbs are words that tell how or when or in what manner something is done, or to what degree or quality a characteristic is exhibited. In short, they tell more about a verb or an adjective. They can also be use to introduce statements, and to smooth the path of reasoning or exposition. All in all, adverbs are very useful words that help to make expression more precise. They are at the opposite pole in grammatical complexity to the verb, since they have a single form that does not change, and is not affected by other words--a welcome relief to the student of Greek.
In English, we can turn any adjective into an adverb by suffixing -ly. From silent, we get silently. In Greek, it is as easy. Simply find the neuter genitive plural, the form with ων, and change the ν to a σ, as shown in the box. Not everything that ends in ωs is an adverb, but many things are.
Sometimes an adverb is used where we might expect an adjective. In describing the positions of angles, Euclid uses adverbs for interior, exterior, alternate and opposite, as shown in the box. Like the English adjectives, these words are derived from prepositions meaning "in" and "out", and you will recognize them in many derived words, especially medical ones.
Adverbs can also be derived from nouns in Greek, and from adjectives used as nouns, by putting the words into the neuter accusative singular case. When you find an accusative in a sentence that is not the object of the verb, nor used with a preposition, suspect that you are dealing with an adjective. Measurements of intervals of space or time very often appear in this form, without a preposition, and their meanings are usually clear. The use of the article &tau:ο with the neuter accusative is quite common. The neuter plural accusative is used the same way with the superlative forms of adjectives. Some examples are given in the box.
Some useful adverbs are shown in the box on the left. These are generally derived from accusatives, but the derivation is now obscure. The word di/ca is used by Euclid in the sense of "bisected".
There are numerical adverbs, of which the first four are shown in the box on the right. Note that, as in English, the pattern changes after "thrice", and the following numerical adverbs all end in -a/kij.
We have already seen that the dative can be used adverbially, to express the manner in which something is done, or the degree of a difference in a comparison. Whole phrases can be used adverbially, of course. Adverbs can be compared like adjectives, with positive, comparative and superlative forms, generally by derivation from the corresponding adjectives. There is no problem in looking up adverbs in a dictionary. If the adverb itself is not listed, then the noun or adjective from which it comes can be found, since these stems do not change like verb stems.
Composed by J. B. Calvert