Verbs

Words that express any sort of action, state, or occurrence are called “verbs”, and there’s usually at least one in any complete sentence:

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Past, Present, and Future Action

There are three basic “tenses” available to Esperanto verbs — past, present, and future — each expressing action happening at different times relative to the speaker:

The Present Tense

Verbs that express action that one has begun but not yet completed (those in the present tense) are marked by the suffix -as:

Note that the form of the verb does not change depending on who is performing it, as it does in English:

The Past Tense

Verbs that express something that happened prior to the moment one is speaking (those in the past tense) are marked by the suffix -is:

The Future Tense

Verbs that express something that will happen after the moment one is speaking (those in the future tense) are marked by the suffix -os:

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Hypothetical Action

The past, present, and future tenses all express actions that actually did, do, or will take place, and collectively make up what grammarians call the “indicative mood”. But there’s also a way to express hypothetical action that probably won’t take place, called the “conditional mood”, which in Esperanto is expressed by -us:

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Desired Action

Verbs expressing something requested are marked by the suffix -u:

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Reported Action: The Sequence of Tenses

In English, when one reports what someone else says or feels, the tense of the quoted action changes depending on the tense of the main verb:

In Esperanto, the tense of the quoted material stays the same as if it were quoted directly:

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Infinitives

When expressing the basic idea of an action without binding it to any particular tense or subject, English either uses the word to followed by the simple form of the verb or attaches -ing to it, as in “I like to dance” or “I like dancing”. In Esperanto, the same idea is expressed by adding -i to the root of the verb:

While there’s nothing technically wrong with using infinitives after prepositions, it may be less jarring for some to express the same idea as an adverb instead:

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Impersonal Action

English often uses the pronoun it when there’s no obvious subject for a sentence, as in “It is freezing in here” and “It would be great if you could come in on Saturday”. Esperanto expresses the same idea by using no pronoun at all:

English “there is”, “there are”, “here is”, etc., is rendered the same way:

except when one wants to call attention to the subject, in which case Esperanto uses jen:

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Participles

Adjectives created from verbs are called “participles”. Most modern European languages, including English, recognize two kinds of participle — those expressing action currently being performed by the nouns they modify, and those expressing completed action, whether being performed by or on the nouns they modify:

In Esperanto, too, there are two basic types of participle: “active” (those being performed by the nouns they modify) and “passive” (those being performed on the nouns they modify by someone or something else). However, both types come in three distinct forms — one to express completed action, one for action in progress, and one for action yet to come:

Participles as Adverbs

A participle can also be used as an adverb by changing the final -a to -e. In this form it tells when or why something happens:

In English, when adverbial participles have their own subjects, they form a “nominative absolute”, that is, an independent part of a sentence that describes the main subject and verb. (Ex., The president impeached, his party set about blocking witnesses.) In Esperanto, however, adverbial participles cannot have their own subject, and nominative absolutes must be rendered as subordinate clauses:

Participles as Nouns

By changing the final -a to -o, a participle can be used as a noun. In this form it expresses a person or thing that performs an action, or on whom it is performed:

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Compound Verbs

Simple verbs in English and Esperanto show not only when the action took place (tense), but the degree of the action’s completion (aspect). For example, the simple past tense generally shows completed action (mi skribis leteron), the present tense action in progress (mi skribas leteron), and the future tense action that will be completed later on (mi skribos leteron). With compound verbs, one can express any degree of completion in any tense:

Note that there is no pluperfect tense in Esperanto, so to convey that one of two actions in the past precedes the other, one needs to use adverbs of time like jam antaŭe (jam alone, usually translated as “already”, can also mean “starting now” or “starting then”):

Compound tenses are much more common in English than in Esperanto, which generally uses them only to underscore the time and completeness of one action in relation to another (akuzi and eniri in the previous example) or to emphasize the agent of a passive action (Kongreso in akuzata de la Kongreso). Otherwise, where English uses a compound verb, Esperanto uses a simple one.

Note that when action in the past continues into the present, the simple present is used, usually in conjunction with a start time.

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Transitive and Intransitive Action

When a person or thing directs action toward another person or thing, the action is said to be “transitive” (i.e., it transits its action onto something else). For example, pay (a fee), watch (a movie), say (the truth). The person or thing being acted on (in the previous examples, fee, movie, and truth) is called the “direct object”.

When the action is not directed toward something else, like be, sit, and recline, it is said to be “intransitive”.

In English, many verbs are both transitive and intransitive, depending on the context:

In Esperanto, a verb is either transitive or intransitive, never both. To make an intransitive verb transitive, one can add -ig- to the root; to make a transitive verb intransitive, one can add -iĝ- to the root:

However, some intransitive verbs can have an object if that object is a noun version of the verb:

or a specific example of the same:

Note, too, that one can use a transitive verb without an object, so as to emphasize only the idea of the action itself:

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