The active voice represents the subject as performing the action of the verb: λούω
a. Under action is included being, as ἡ ὁδὸς μακρά_ ἐστι
Active verbs are transitive or intransitive ( cross920).1705
The action of a transitive verb is directed immediately upon an object, as τύπτω τὸν παῖδα
The object of a transitive verb is always put in the accusative ( cross1553).1707
The action of an intransitive verb is not directed immedi-ately upon an object. The action may be restricted to the subject, as ἀλγῶ
Many verbs are used in the active voice both transitively and intransitively. So, in English, turn, move, change. Cp. cross1557 ff.
a. The distinction between transitive and intransitive verbs is a grammatical convenience, and is not founded on an essential difference of nature.1709
Active verbs ordinarily transitive are often used intransitively:
a. By the ellipsis of a definite external object, which in some cases may be employed, as ἄγειν (τὸ στράτευμα)
αἴρειν τῷ στρατῷ
ἐλαύνων ἱδροῦντι τῷ ἵππῳ
b. πρά_ττειν, ἔχειν with adverbs often mean
c. Many other transitive verbs may be used absolutely, i.e. with no definite object omitted, as νι_κᾶν
d. In poetry many uncompounded transitive verbs are used intransitively. Many intransitive verbs become transitive when compounded with a prep., especially when the compound has a transferred sense, 1559. In some verbs 1st aorist and 1st perfect are transitive, 2d aorist and 2d perfect are intransitive.
Instead of the active, a periphrasis with γίγνεσθαι may be used, often to express solemnity.
Causative Active.—The active may be used of an action performed at the bidding of the subject: Κῦρος τὰ βασίλεια κατέκαυσεν
An infinitive limiting the meaning of an adjective is usually active where English employs the passive (cp. cross2006).
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].