Reference grammars of the language include the Plena Analiza Gramatiko (Complete Analytical Grammar) by Kálmán Kalocsay and Gaston Waringhien, and the Plena Manlibro de Esperanta Gramatiko (Complete Handbook of Esperanto Grammar) by Bertilo Wennergren.
These concepts are illustrated below.
Esperanto uses the Latin alphabet. The orthography utilizes diacritics, which make digraphs such as English ch and sh unnecessary. (Alternatively, Esperanto may be written with English-like digraphs in h rather than with diacritics, but this is seldom seen outside email.) Over all, the Esperanto alphabet resembles the Czech alphabet, but with circumflexes rather than háčeks on the letters ĉ, ŝ; Western-based ĝ, ĵ in place of Czech dž, ž; and ĥ for Czech ch. These letters are unique to Esperanto, though it also has a letter ŭ that is shared with the Belarusian Łacinka alphabet.
Zamenhof suggested Italian as a model for Esperanto pronunciation.
La is used:
The article is also used for inalienable possession of body parts and kin terms, where English would use a possessive adjective:
The article la, like the demonstrative adjective tiu (this, that), nearly always occurs at the beginning of the noun phrase, but this is not required by the grammar, and exceptions occur in poetry.
There is no grammatically required indefinite article: homo means either "human being" or "a human being", depending on the context, and similarly the plural homoj means "human beings" or "some human beings". The words iu and unu (or their plurals iuj and unuj) may be used somewhat like indefinite articles, but they're closer in meaning to "some" and "a certain" than to English "a".
Each root word has an inherent part of speech: nominal, adjectival, verbal, or adverbial. These must be memorized explicitly and affect the use of the part-of-speech suffixes. With an adjectival or verbal root, the nominal suffix -o indicates an abstraction: parolo (an act of speech, one's word) from the verbal root paroli (to speak); belo (beauty) from the adjectival root bela (beautiful); whereas with a noun, the nominal suffix simply indicates the noun. Nominal or verbal roots may likewise be modified with the adjectival suffix -a: reĝa (royal), from the nominal root reĝo (a king); parola (spoken). The various verbal endings mean to be when added to an adjectival root: beli (to be beautiful); and with a nominal root they mean to act as the noun, to use the noun, etc., depending on the semantics of the root: reĝi (to reign). There are relatively few adverbial roots, so most words ending in -e are derived: bele (beautifully). Often with a nominal or verbal root, the English equivalent is a prepositional phrase: parole (by speech, orally); vide (visually, by sight); reĝe (like a king, royally).
A suffix -j following the noun or adjective suffixes -o or -a makes a word plural. Without this suffix, a countable noun is understood to be singular. Direct objects take an accusative case suffix -n, which goes after any plural suffix. (The resulting sequence -ojn rhymes with English coin, and -ajn rhymes with fine.)
Adjectives agree with nouns. That is, they are plural if the nouns they modify are plural, and accusative if the nouns they modify are accusative. Compare bona tago; bonaj tagoj; bonan tagon; bonajn tagojn (good day/days). This requirement allows for free word orders of adjective-noun and noun-adjective, even when two noun phrases are adjacent in subject-object-verb or verb-subject-object clauses:
Agreement clarifies the syntax in other ways as well. Adjectives take the plural suffix when they modify more than one noun, even if those nouns are all singular:
A predicative adjective does not take the accusative case suffix even when the noun it modifies does:
The meanings of part-of-speech affixes depend on the inherent part of speech of the root they are applied to. For example, brosi (to brush) is based on a nominal root (and therefore listed in modern dictionaries under the entry broso), whereas kombi (to comb) is based on a verbal root (and therefore listed under kombi). Change the suffix to -o, and the similar meanings of brosi and kombi diverge: broso is a brush, the name of an instrument, whereas kombo is a combing, the name of an action. That is, changing verbal kombi (to comb) to a noun simply creates the name for the action; for the name of the tool, the suffix -ilo is used, which derives words for instruments from verbal roots: kombilo (a comb). On the other hand, changing the nominal root broso (a brush) to a verb gives the action associated with that noun, brosi (to brush). For the name of the action, the suffix -ado will change a derived verb back to a noun: brosado (a brushing). Similarly, an abstraction of a nominal root (changing it to an adjective and then back to a noun) requires the suffix -eco, as in infaneco (childhood), but an abstraction of an adjectival or verbal root merely requires the nominal -o: belo (beauty). Nevertheless, redundantly affixed forms such as beleco are acceptable and widely used.
In addition, most verbs are inherently transitive or intransitive. As with the inherent part of speech, this is not apparent from the shape of the verb and must simply be memorized. Transitivity is changed with the suffixes -igi (the transitivizer/causative) and -iĝi (the intransitivizer/middle voice):
A limited number of basic adverbs do not end with -e, but with an undefined part-of-speech ending -aŭ. Not all words ending in -aŭ are adverbs, and most of the adverbs that end in -aŭ have other functions, such as hodiaŭ "today" [noun or adverb] or ankoraŭ "yet, still" [conjunction or adverb]. About a dozen other adverbs are bare roots, such as nun "now", tro "too, too much", not counting the adverbs among the correlatives. (See special Esperanto adverbs.)
Other parts of speech occur as bare roots, without special suffixes. These are the pronouns (mi "I"), prepositions (al "to"), conjunctions (kaj "and"), interjections (ho "oh"), and numerals (du "two"). (The final -i found on pronouns is not a suffix, but part of the root.) There are also several "grammatical particles" which don't fit neatly into any category, and which must generally precede the words they modify, such as ne (not), ankaŭ (also), nur (only), eĉ (even).
| singular | plural | ||
|---|---|---|---|
| first person | mi (I) | ni (we) | |
| second person | vi (you) | ||
| third person | masculine | li (he) | ili (they) |
| feminine | ŝi (she) | ||
| epicene | ĝi (it, s/he) | ||
| indefinite | oni (one)* | ||
| reflexive | si (self) | ||
Personal pronouns take the accusative suffix -n like nouns do: min (me), lin (him), ŝin (her). Possessive adjectives are formed with the adjectival suffix -a: mia (my), ĝia (its), nia (our). These agree with their noun like any other adjective: ni salutis liajn amikojn (we greeted his friends). Esperanto does not have separate forms for the possessive pronouns; this sense is generally (though not always) indicated with the definite article: la mia (mine).
The reflexive pronoun is used, in non-subject phrases only, to refer to back to the subject, usually only in the third and indefinite persons:
The indefinite pronoun is used when making general statements, and is often used where English would have the subject it with a passive verb,
Zamenhof created an informal second-person singular pronoun ci (thou), and capitalized the formal singular pronoun Vi, following usage in most European languages, but these forms are rarely seen today.
Ĝi is used principally with animals and objects. Zamenhof also prescribed it to be the epicene (gender-neutral) third-person singular pronoun, for use when the sex of an individual is unknown, or to refer to an epicene noun such as persono (person). However, it is generally only used for children:
Prepositions should be used with a definite meaning. When no one preposition is clearly correct, the indefinite preposition je should be used:
Alternatively, the accusative may be used without a preposition:
Note that although la trian (the third) is in the accusative, de majo (of May) is still a prepositional phrase, and so the noun majo remains in the nominative case.
A frequent use of the accusative is in place of al (to) to indicate the direction or goal of motion (allative construction). It is especially common when there would otherwise be a double preposition:
The accusative/allative may stand in for other prepositions as well, especially when they have vague meanings that don't add much to the clause. Adverbs, with or without the case suffix, are frequently used in place of prepositional phrases:
Occasionally a new preposition is coined. As a bare root may indicate a preposition or interjection, removing the grammatical suffix from another part of speech can be used to derive a preposition or interjection. For example, from fari (to do, to make) we get the preposition far (done by), a more precise substitute for de (of, by, from).
Verbs do not change form according to their subject. I am, we are, and he is are simply mi estas, ni estas, and li estas, respectively. Impersonal subjects are not used: pluvas (it is raining); estas muso en la domo (there's a mouse in the house).
| Indicative | Active participle | Passive participle | Infinitive | Jussive | Conditional | |
|---|---|---|---|---|---|---|
| Past | -is | -inta | -ita | -i | -u | -us |
| Present | -as | -anta | -ata | |||
| Future | -os | -onta | -ota |
The verbal forms may be illustrated with the root esper- (hope):
A verb can be made emphatic with the particle ja (indeed): mi ja esperas (I do hope), mi ja esperis (I did hope).
The jussive mood, called the volitive in Esperanto, is used for wishing and requesting, and serves as the imperative. It covers some of the uses of the subjunctive in European languages:
It is becoming increasingly common to replace esti-plus-adjective with a verb: la ĉielo estas blua or la ĉielo bluas (the sky is blue). This is a stylistic rather than grammatical change in the language, as the more economical verbal forms were always found in poetry.
Active and passive pairs can be illustrated with the transitive verb haki (to chop). Picture a woodsman approaching a tree with an axe, intending to chop it down. He is hakonta (about to chop) and the tree is hakota (about to be chopped). While swinging the axe, he is hakanta (chopping) and the tree hakata (being chopped). After the tree has fallen, he is hakinta (having chopped) and the tree hakita (chopped).
Adjectival participles agree with nouns in number and case, just as other adjectives do:
These are not used as often as their English equivalents. For "I am going to the store", you would normally use the simple present mi iras in Esperanto.
The tense and mood of esti can be changed in these compound tenses:
Although such periphrastic constructions are familiar to speakers of most European languages, the option of contracting [esti + adjective] into a verb is often seen for adjectival participles:
The most common of these synthetic forms are:
| Simple verb | Progressive aspect | Perfect aspect | Prospective aspect | |
|---|---|---|---|---|
| Present tense | mi kaptas (I catch) | mi kaptantas (I am catching) | mi kaptintas (I have caught) | mi kaptontas (I am about to catch) |
| Past tense | mi kaptis (I caught) | mi kaptantis (I was catching) | mi kaptintis (I had caught) | mi kaptontis (I was about to catch) |
| Future tense | mi kaptos (I will catch) | mi kaptantos (I will be catching) | mi kaptintos (I will have caught) | mi kaptontos (I will be about to catch) |
| Conditional mood | mi kaptus (I would catch) | mi kaptantus (I would be catching) | mi kaptintus (I would have caught) | mi kaptontus (I would be about to catch) |
Infinitive and jussive forms are also found. There is a parallel passive paradigm.
A nominal participle indicates one who participates in the action specified by the verbal root. For example, esperinto is a "hoper" (past tense), or one who had been hoping. (In the early years of the language, such forms were assumed to be masculine, but that is no longer the case.)
This can also be illustrated with the verb prezidi (to preside). Just after the recount of the 2000 United States presidential election:
Note that this example is somewhat artificial, since the customary word for 'president' (of a country) is the tense-neutral word prezidento, which is officially a separate root, not a derivative of the verb prezidi. However, prezidanto is typically used for the presidents of organizations other than sovereign countries, and prezidinto is used for former presidents in such contexts.
The conditional forms are infrequent, but their regular derivation ensures that they can be readily understood, even if rarely needed. No European language has conditional participles; in English, words like prezidunto must be expressed periphrastically.
Likewise, some Esperantists have proposed a tenseless participle, though only for active-participle role. The element -ento is not officially a participle or even a separate morpheme, but it is very common and is sometimes regarded as a suffix. It frequently occurs in words for occupations where one would not wish to specify tense, such as prezidento or studento (student). Since there is often a verb derived from the same Latin root, in these cases prezidi (to preside) and studi (to study), this -ento has occasionally been proposed as a tense-neutral active participle by analogy with the temporal participles -anto, -into, -onto.
However, even if the participial paradigm were to be extended in this way, it would be asymmetric in that there can be no direct passive counterpart to *-ento because the expected -eto already exists as the diminutive suffix. The nearest equivalent is the middle voice suffix -iĝi, which is commonly used as a generic passive. Unlike the active case, where a few new nouns like prezidento were sufficient to avoid making the language overly specific, a need for a neutral passive participle was felt in the verbs. For example, there was heated debate for several decades as to whether "I was born in 19xx" should be mi estis naskita (I had been born) or mi estis naskata (literally 'I was being born'), with the French and Germans generally holding opposite opinions deriving from usage in their native languages. Today, people sidestep the issue with the temporally neutral mi naskiĝis (I was born).
*Mi ne faris nenion ajn (I didn't do nothing) is considered ungrammatical.
The word ne comes before the word it negates, with the default position being before the verb:
The latter will frequently be reordered as ne tion mi skribis depending on the flow of information.
"Wh" questions are asked with one of the interrogative/relative (ki-) correlatives. They are commonly placed at the beginning of the sentence, but different word orders are allowed for stress:
Yes/no questions are marked with the conjunction ĉu (whether):
Such questions can be answered jes (yes) or ne (no) in the European fashion of aligning with the polarity of the answer, or ĝuste (correct) or malĝuste (incorrect) in the Japanese fashion of aligning with the polarity of the question:
Note that Esperanto questions may have the same word order as statements.
However, unlike prepositions, they allow the accusative case, as in the following example from Don Harlow:
These are grammatically numerals, not nouns, and as such do not take the accusative case suffix. However, unu (and only unu) is sometimes used adjectivally or demonstratively, meaning "a certain", and in such cases it may take the plural affix -j, just as the demonstrative pronoun tiu does:
Note that these are not numerals but nouns, and behave as such. An unambiguous international system is provided by the metric prefixes, and the nonce numerals meg (miliono) and gig (miliardo) are occasionally derived from them.
The particle po is used to mark distributive numbers, that is, the idea of distributing a certain number of items to each member of a group. Consequently the logogram @ is not used (except in email addresses, of course):
Note that particle po forms a phrase with the numeral tri and is not a preposition for the noun phrase tri pomojn, so it does not prevent a grammatical object from taking the accusative case.
Implied comparisons are made with tre (very) and tro (too [much]).
Phrases like "The more people, the smaller the portions" and "All the better!" are translated using ju and des in place of "the":
There is very little about Esperanto that is not European in origin. Although it is billed as a neutral international language, its vocabulary, syntax, and semantics derive predominantly from European national languages. Roots are typically Romance or Germanic in origin, with a bit of Slavic and Classical Greek. The semantics shows a heavier Slavic influence.
It is often claimed that there are elements of the grammar which are not found in these language families. Frequently mentioned is Esperanto's agglutinative morphology and subsequent lack of ablaut (internal inflection of its roots). Ablaut is an element of all the source languages; an English example is song sing sang sung. However, the majority of words in all European languages inflect without ablaut, as cat, cats and walk, walked do in English. (This is the so-called strong-weak dichotomy.) Historically, many European languages have expanded the range of their 'weak' inflections, and Esperanto has merely taken this development closer to its logical conclusion, with the only remaining ablaut being frozen in a few sets of semantically related roots such as pli, plu, plej (more, more, most), tre, tro (very, too much), and in the verbal morphemes -as, -anta, -ata; -is, -inta, -ita; -os, -onta, -ota; and -us. (This system can be extended further, with conditional participles -unta and -uta derived from the conditional mood in -us.)
Other features often cited as being nonstandard for a European language, such as the dedicated suffixes for different parts of speech, or the -o suffix for singular nouns, actually do occur in some European languages, with similar systems found especially in Russian feminine and neuter nouns.
Perhaps the best candidate for a "non-European" feature, the accusative plural in -jn, is derived through leveling of standard European grammatical structures. The Esperanto nominal-adjectival paradigm as a whole is taken from Greek: Esperanto nominative singular muso (mouse) vs. Greek mousa (muse), nominative plural musoj vs. Greek mousai, and accusative singular muson vs. Greek mousan. (Latin had a very similar setup.) However, Esperanto does not have a discrete accusative plural suffix analogous with Greek mous-ās; rather, it compounds the simple accusative and plural suffixes: mus-o-j-n. This morphology does not occur in any of Esperanto's source language families, but it is formally similar to Hungarian and Turkish grammar—that is, it is similar in its mechanics, but not in the details. However, none of these proposed "non-European" elements of the original Esperanto proposal were actually taken from non-European or non-Indo-European languages.
East Asian languages may have had some influence on the development of Esperanto grammar after its creation. The principally cited candidate is the replacement of predicate adjectives with verbs, such as la ĉielo bluas (the sky is blue) for la ĉielo estas blua and mia filino belu! (may my daughter be beautiful!) for the mia filino estu bela! mentioned above. This is a regularization of existing grammatical forms and was always found in poetry; if there has been an Asian influence, it has only been in the spread of such forms, not in their origin.
The Pater noster, from the first Esperanto publication in 1887, illustrates many of the grammatical points presented above, and should be readable without translation:
The morphologically complex words (see Esperanto word formation) are:
| sanktigata | |||
| sankt- | -ig- | -at- | -a |
| holy | causative | passive participle | adjective |
| "made holy" | |||
| fariĝu | ||
| far- | -iĝ- | -u |
| do | middle voice | jussive |
| "be done" | ||
| ĉiutagan | |||
| ĉiu- | tag- | -a | -n |
| every | day | adjective | accusative |
| "daily" | |||
| ŝuldantoj | |||
| ŝuld- | -ant- | -o | -j |
| owe | active participle | noun | plural |
| "debtors" | |||
| liberigu nin | ||||
| liber- | -ig- | -u | ni | -n |
| free | causative | jussive | we | accusative |
| "free us" | ||||
| la malbono | |||
| la | mal- | bon- | -o |
| generic article | antonym | good | noun |
| "evil" | |||