Example.—Ĉiuj, kiuj ŝin vidis povis pensi, ke ili vidas la patrinon = All who saw her could think that they saw (see) her (the) mother. In this sentence, what did they think? Their thought was, "We see her mother," not "We saw her mother." The sight was present to them, hence ili vidas.
221. Present in place of the Past.—If it is a question of the truth of all time, or of a fact existing at the moment spoken of, English generally uses the Past tense, but in Esperanto the Present is always employed.
Examples.—Ni eksciis, ke vi estas en Londono ok tagojn = We learnt that you were (are) in London for eight days. Ni kredis, ke vi estas kuracisto = We believed that you were (are) a doctor. Li instruis nin, he ĉiam oni devas esti indulga = He taught us that one must always be forbearing (merciful).
222. The Present tense (compound) is formed by the auxiliary esti = to be and one of the three participles, -ANTA, -INTA, -ONTA. The compound tenses are seldom used in Esperanto, and their use is to be avoided if the simple tenses suffice to convey our meaning. Their use, therefore, is confined to giving exactitude to the time of an action or to an idea (see par. [169]).
Examples.—Li estas vojaĝanta = He is travelling. The simple form, Li vojaĝas, might mean that he travels generally, but possibly is not at this moment on his way to any place. If, therefore, we wish to convey that he is actually on his way to some place, we use the compound form, or some additional word, as nun, e.g., li nun vojaĝas. Kiam la abeloj estas forflugontaj, ili zumadas laŭte = When bees are about to fly away, they (are accustomed to) hum loudly (see par. [216] (a)). Esti skribanta = To be writing.
The Past.
223. The Past tense (simple) ends in -IS. It expresses something that has passed. It is used for the three tenses in English; the past, imperfect, and perfect; and sometimes for the pluperfect, if its use does not cause ambiguity.
Examples.—Mi skribis = I wrote, I was writing, or, I have written. Li venis antaŭ du horoj = He came two hours ago. Pluvis hieraŭ = It rained yesterday. Se li estis malsana, li ne povis veni = If he was ill, he could not come. Ĉu vi lin vidis? = Did you see (or, have you seen) him? Li foriris, antaŭ ol mi alvenis = He had left before I arrived. Mi promenis hieraŭ, kaj renkontis vian amikon = I took a walk (or, I was walking, better promenadis) yesterday, and met your friend.
224. The Past tense (compound) is formed by the auxiliary verb esti = to be and one of the three participles, -ANTA, -INTA, -ONTA. This form should not be used when the simple form suffices to convey the required meaning. It is better employed only when we wish to give to an expression more exactitude as regards the state of the subject at the time of the principal action than is conveyed by the simple form (see pars. [169], [226] (a)).
Examples.—Kiam li estis fininta sian laboron, li iris hejmen = When he had finished his work, he went home. Mi estis skribanta leteron, kiam okazis tertremo = I was writing a letter when an earthquake took place. Ili interkonsentis kaj estis enirontaj la landon, sed io okazis, kio ilin malhelpis = They mutually agreed, and were about to enter the country, but something happened which prevented them.