[1473.] The object accusative of the active voice becomes the subject of the passive voice ([1125]); and the predicate accusative of the active voice becomes a predicate nominative with the passive voice ([1167]).
Thus (a.) in the active construction: illum laudābunt bonī, hunc etiam ipsī culpābunt malī, Pl. B. 397, the one the good will praise, the other e’en the bad themselves will blame. In the passive: laudātur ab hīs, culpātur ab illīs, H. S. 1, 2, 11, he’s praised by some, by others blamed. Active: cīvēs Rōmānōs interficiunt, 7, 3, 1, they slay some citizens of Rome. Passive: Indutiomarus interficitur, 5, 58, 6, Indutiomarus is slain. (b.) Active: mīlitēs certiōrēs facit, 3, 5, 3, he informs the soldiers. Passive: certior factus est, 2, 34, he was informed.
[1474.] Verbs which have two accusatives, one of the person and one of the thing in the active voice, generally have the person as subject in the passive, less frequently the thing: see [1171].
[1475.] An emphasizing or defining accusative, or an accusative of extent or duration, is occasionally made the subject of a passive: as,
haec illīc est pugnāta pugna, Pl. Am. 253, this fight was fought off there ([1140]). tōta mihī dormītur hiems, Mart. 13, 59, 1, all winter long by me is slept, i.e. tōtam dormiō hiemem ([1151]).
[1476.] The person by whom the action is done is put in the ablative with ab or ā ([1318]); the thing by which it is done is put in the instrumental ablative ([1377]); as,
([a.]) nōn numquam latrō ā viātōre occīditur, Mil. 55, once in a while the robber gets killed by the wayfarer. respondit, ā cīve sē spoliārī mālle quam ab hoste vēnīre, Quintil. 12, 1, 43, he said in reply that he would rather be plundered by a Roman than sold by an enemy ([1471]). (b.) ūnīus virī prūdentiā Graecia līberāta est, N. 2, 5, 3, Greece was saved from slavery by the sagacity of a single man, i.e. Themistocles. Very often, however, the person or thing is not expressed, particularly with impersonals.
[1477.] When the person is represented as a mere instrument, the ablative is used without ab ([1378]); and when collectives, animals, or things without life are personified, the ablative takes ab ([1318]): as,
([a.]) neque vērō minus Platō dēlectātus est Diōne, N. 10, 2, 3, and Plato on his part was just as much bewitched with Dion. (b.) eius ōrātiō ā multitūdine et ā forō dēvorābātur, Br. 283, his oratory was swallowed whole by the untutored many and by the bar.