The Latin Deponent Verb is a verb that has a passive voice form but an active voice meaning. Luckily, not many Deponent Verbs are encountered in elementary Latin study, the kind of Latin studied in High School particularly. The word Deponent is itself of Latin derivation from the word “depono” (deponere) literally meaning “to lay” or “put down.” Think of deponent verbs as having “laid down” their passive meaning to embrace an active meaning.
One particularly common Deponent verb is “loquor” which means “to speak.” Regular Latin verbs typically have four principal parts. However, Deponent Verbs have only three; the first, the second, and the fourth. This is because that is all that is necessary to form the four remaining characteristics of a verb (person, number, tense, and mood). The third principal part is used to form the perfect tense system of the active voice. In the passive voice, the perfect tense system uses the past participle or the fourth principal part. Therefore, no third principal part is needed.
The principal parts of “loquor” are:
loquor, loqui, locutus sum
Loquor conjugates just as any other verb of the passive voice for each of the six tenses. However, recall that although a Deponent Verb has a passive form, it has an active meaning. For example:
Caesar viro senecto loquitur. (Present)
Caesar is speaking to the old man.
Caesar viro senecto loquebatur. (Imperfect)
Caesar was speaking to the old man.
Caesar viro senecto loquetur. (Future)
Caesar will speak to the old man.
Caesar viro senecto locutus est. (Perfect)
Caesar spoke to the old man.
Caesar viro senecto locutus erat. (Pluperfect)
Caesar had spoken to the old man.
Caesar viro senecto locutus erit. (Future Perfect)
Caesar will have spoken to the old man.
Again, notice the passive forms of the verb but the active translation and meaning.