UD for Esperanto 
As of July 2025, Esperanto UD contains two documents (Manufest de Prago and Cairo) annotated with Universal Dependencies.
Tokenization and Word Segmentation
- Esperanto words are delimited by whitespace or punctuation, and no tokens in any of the UD Esperanto corpus currently contain whitespace. Only a few multiword tokens should be used for Esperanto clitics, such as dank’al (danke + al, “thanks to”), or l’ (reduced form of the definite article “la”).
Morphology
Tags
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Esperanto uses all 17 universal POS categories.
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PART is annotated to ĉi, the adverbial particle for expressing proximity, making the distinctiong between tiu “that” and ĉi tiu “this”.
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AUX is annotated to the copula esti.
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DET is annotated to the definite article la (Esperanto has no indefinite article), and correlatives, such as iu “some,” tio “that,” tiu “that person,” ĉiu “all,” etc. when used before a noun.
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PRON is annotated to pronouns (e.g., Ili estas lernantoj. “They are students.”) and stand-alone correlatives functioning as demonstrative pronouns (e.g., Tiuj estas lernantoj. “Those people are students.”)
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Each participle is annotated with the appropriate tag according to its function in the sentence it appears, which may be revised in future.
In Esperanto, the word-ending morpheme of a word indicates its part of speech: Nouns end with -o (when nominative singular), infinitive verbs with -i, adjectives with -a, and adverbs with -e. For example,with the root aŭd-, aŭdo means “hearing,” aŭdi means “to hear,” aŭda means “auditory,” and aŭde means “by ear.”
Nouns:
Suffixes on nouns indicate their case and number: Nouns ending with -o are nominative singular, those with -oj are nominative plural, -on accusative singular, and -ojn accusative plural. For example,
Esploristo faras eksperimenton. “A researcher conducts an experiment.”
The noun esploristo is a nominative singular, functioning as the subject of the verb faras, while the noun eksperimenton is an accusative singular, functioning as the object of the same verb. For another example,
Esploristoj faras eksperimentojn. “Researchers conduct experiments.”
The noun esploristoj is a nominative plural, functioning as the subject of the verb faras (Esperanto does not have subject-verb agreement). The noun eksperimentojn is an accusative plural, functioning as the object of the same verb.
Adjectives:
Adjectives agree with the nouns they modify in terms of their case and number: Adjectives ending with -a are nominative singular, those with -aj are nominative plural, -an accusative singular, and -ajn accusative plural. For example,
Laborema esploristo faras malfacilan eksperimenton. “A hard-working researcher conducts a difficult experiment.”
The nominative singular adjective laborema agrees with the nominative singular noun esploristo, while the accusative singular adjective malfacilan agrees with the accusative singular noun experimenton. For another example,
Laboremaj esploristoj faras malfacilajn eksperimentojn. “Hard-working researchers conduct difficult experiments.”
The nominative plural adjective laboremaj agrees with the nominative plural noun esploristoj, while the accusative plural adjective malfacilajn agrees with the accusative plural noun experimentojn.
Adjectives also agree with the subject when they are the complement of the copula esti. For example,
Ĉi tiuj eksperimentoj estas malfacilaj. “These experiments are difficult.”
The nominative plural adjective “malfacilaj” agrees with the nominative plural noun “eksperimentoj.”
Verbs:
Suffixes on verbs indicate their mood and tense: verbs ending with -i are their infinite forms, -as indicates the indicative present, -is the indicative past, -os the indicative future, -us the subjunctive, and -u the imperative. For example,
Esploristo faras eksperimenton. “A researcher conducts an experiment.”
Esploristo faris eksperimenton. “A researcher conducted an experiment.”
Esploristo faros eksperimenton. “A researcher will conduct an experiment.”
Eploristo farus eksperimenton. “A researcher would conduct an experiment.”
Faru eksperimenton, mi petas. “Conduct an experiment, please.”
(To be continued)
Features
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Syntax
Standard deprels are used.
Treebanks
There are 2 Esperanto UD treebanks: