There are in Esperanto six participles, three active and three passive, corresponding to three tenses. They are formed in the Active by means of the endings -ant, -int, and -ont, and in the Passive by means of the endings -at, -it, -ot, with the addition of the adjectival termination -a. Thus:

Active.Present.Past.Future.
vidanta, seeingvidinta, having-seenvidonta, about-to-see
Passive.
vidata, (being) seenvidita, (having-been) seenvidota, (about-to-be) seen

The Participles may be used either as Nouns, Adjectives, or Adverbs, the terminations -o, -a, -e being added to the participial endings as required. When used as nouns or adjectives, they of course take the sign of the Plural (-j) and of the Accusative (-n) when the construction of the sentence so requires. Ex.:

(1) Active. En la venonta jaro, in the coming year. La parolanto, the speaker. La aŭskultantoj, the audience (lit., listeners). Mi vidis lin skribantan, I saw him writing. Li foriris kurante, he went off at a run. Li revenis ne vidinte sian amikon, he returned without having seen his friend.

(2) Passive. La ekzamenato, the examinee. La mortigitoj kaj vunditoj, the killed and wounded. Estimata sinjoro, dear (lit., esteemed) sir. Frapote, li sin defendis, about to be struck, he defended himself. Mi aŭdis tiun himnon kantatan, I heard that hymn sung.

Compound Tenses.

The Compound Tenses are formed by means of the auxiliary verb esti, to be. Thus, by the combination of the participles with the six tenses and moods, we obtain thirty-six compound tenses, enabling us to express with the utmost precision any time-relation whatsoever. We have in all:

li estas,
or estus,
or estis,
or estu,
or estos
or esti
vidanta or vidata
vidinta or vidita
vidonta or vidota

The use of the participles is very easy when once one grasps the fact that the auxiliary esti serves to denote the particular division of time, or the particular manner, of the occurrence of the action denoted by the participle. Ex.:

The word by after a Passive is translated by the preposition de. Thus: The wood was being chopped by the boy, la ligno estis hakata de la knabo. He has been seen by all, li estas vidita de ĉiuj.