Esperanto grammar

Esperanto is a constructed language intended for international communication. It was designed with a highly regular grammar, and as such is considered an easy language to learn.
Each part of speech has a characteristic ending: nouns end with "‑o"; adjectives with "‑a"; present‑tense indicative verbs with "‑as", and so on.
An extensive system of prefixes and suffixes may be freely combined with roots to generate vocabulary, so that it is possible to communicate effectively with a vocabulary of 400 to 500 root words. The original vocabulary of Esperanto had around 900 root words, but was quickly expanded.
Reference grammars include the "" () by Kálmán Kalocsay and Gaston Waringhien, and the "Plena Manlibro de Esperanta Gramatiko" () by Bertilo Wennergren.
Grammatical summary.
Esperanto has an agglutinative morphology, no grammatical gender, and simple verbal and nominal inflections. Verbal suffixes indicate four moods, of which the indicative has three tenses, and are derived for several aspects, but do not agree with the grammatical person or number of their subjects. Nouns and adjectives have two cases, nominative/oblique and accusative/allative, and two numbers, singular and plural; the adjectival form of personal pronouns behaves like a genitive case. Adjectives generally agree with nouns in case and number. In addition to indicating direct objects, the accusative/allative case is used with nouns, adjectives and adverbs for showing the destination of a motion, or to replace certain prepositions; the nominative/oblique is used in all other situations. The case system allows for a flexible word order that reflects information flow and other pragmatic concerns, as in Russian, Greek, and Latin.
Script and pronunciation.
Esperanto uses the Latin alphabet with six additional lettersĉ, ĝ, ĥ, ĵ, ŝ, and ŭand does not use the letters q, w, x, or y.
Zamenhof suggested Italian as a model for Esperanto pronunciation.
The article.
Esperanto has a single definite article, "la", which is invariable. It is similar to English "the".
"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), occurs at the beginning of the noun phrase.
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". This use of "unu" corresponds to English "a" when the "a" indicates a specific individual.
For example, it is used to introduce new participants ("Unu viro ekvenis al mi kaj diris ..." 'A man came up to me and said ...').
Parts of speech.
The suffixes "‑o", "‑a", "‑e", and "‑i" indicate that a word is a noun, adjective, adverb, and infinitive verb, respectively. Many new words can be derived simply by changing these suffixes. Derivations from the word "vidi" (to see) are "vida" (visual), "vide" (visually), and "vido" (vision).
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" (by sight, visually); "reĝe" (like a king, royally).
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.
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 prepositions "(al" "to"), conjunctions "(kaj" "and"), interjections "(ho" "oh"), numerals "(du" "two"), and pronouns "(mi" "I"—The final "-i" found on pronouns is not a suffix, but part of the root). There are also several grammatical "particles" that fit neatly into no category, and which must generally precede the words they modify, such as "ne" (not), "ankaŭ" (also), "nur" (only), "eĉ" (even).
The part-of-speech endings may double up. Apart from the "-aŭ" suffix, where adding a second part-of-speech ending is nearly universal, this happens only occasionally. For example, "vivu!" "viva!" (the volitive of "vivi" 'to live') has a nominal form "vivuo" (a cry of 'viva!') and a doubly verbal form "vivui" (to cry 'viva!').
Nouns and adjectives.
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 that they modify are plural, and accusative if the nouns that 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 also. 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 that it modifies does:
Pronouns.
There are three types of pronouns in Esperanto: personal "(vi" "you"), demonstrative "(tio" "that", "iu" "someone"), and relative/interrogative "(kio" "what").
According to the fifth rule of the "Fundamento de Esperanto":
Personal pronouns.
The Esperanto personal pronoun system is similar to that of English, but with the addition of a reflexive pronoun.
 Zamenhof introduced the singular second-person pronoun "ci" to be used in translations from languages where the T–V distinction is important, and added it in the "Dua Libro" in 1888 clarifying that "this word is only found in the dictionary; in the language itself it is hardly ever used". It has never been widely used, even by Zamenhof himself, who didn't include it as a pronoun in the 5th rule of the "Fundamento" and in his 28th "Lingva Respondo", published in 1908, recommended to use only "vi". The normal usage is to use "vi" regardless of number or formality. However, especially in some circles, people have begun to use "ci" in practical speech.
Personal pronouns take the accusative suffix "-n" as 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 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,
With impersonal verbs, no pronoun is used:
Here the rain is falling by itself, and that idea is conveyed by the verb, so no subject pronoun is needed.
When not referring to humans, "ĝi" is mostly used with items that have physical bodies, with "tiu" or "tio" used otherwise. Zamenhof proposed that "ĝi" could also be used as an epicene (gender-neutral) third-person singular pronoun, meaning for use when the gender of an individual is unknown or for when the speaker simply doesn't wish to clarify the gender. However, this proposal is only common when referring to children:
When speaking of adults or people in general, in popular usage it is much more common for the demonstrative adjective and pronoun "tiu" ("that thing or person that is already known to the listener") to be used in such situations. This mirrors languages such as Japanese, but it's not a method that can always be used. For example, in the sentence
the word "tiu" would be understood as referring to someone other than the person speaking (like English pronouns "this" or "that" but also referring to people), and so cannot be used in place of "ĝi", "li" or "ŝi." See gender-neutral pronouns in Esperanto for other approaches.
Other pronouns.
The demonstrative and relative pronouns form part of the correlative system, and are described in that article. The pronouns are the forms ending in "-o" (simple pronouns) and "-u" (adjectival pronouns). Their accusative case is formed in "-n," but the genitive case ends in "-es," which is the same for singular and plural and does not take accusative marking. Compare the nominative phases "lia domo" (his house) and "ties domo" (that one's house, those ones' house) with the plural "liaj domoj (his houses) and "ties domoj (that one's houses, those ones' houses), and with the accusative genitive "lian domon" and "ties domon."
Prepositions.
Although Esperanto word order is fairly free, prepositions must come at the beginning of a noun phrase. Whereas in languages such as German, prepositions may require that a noun be in various cases (accusative, dative, "and so on)," in Esperanto all prepositions govern the nominative: "por Johano" (for John). The only exception is when there are two or more prepositions and one is "replaced" by the accusative.
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 also, especially when they have vague meanings that add not much to the clause. Adverbs, with or without the case suffix, are frequently used instead of prepositional phrases:
Both "por" and "pro" often translate English 'for'. However, they distinguish "for a goal" (looking forward in time, or causing: "por") and "for a cause" (looking back in time, or being caused by: "pro"): To vote "por" your friend means to cast a ballot with their name on it, whereas to vote "pro" your friend would mean to vote in their place or as they asked you to.
The preposition most distinct from English usage is perhaps "de", which corresponds to English "of, from, off," and "(done) by":
However, English "of" corresponds to several Esperanto prepositions also: "de, el" (out of, made of), and "da" (quantity of, unity of form and contents):
The last of these, "da", is semantically Slavic and is difficult for Western Europeans, to the extent that even many Esperanto dictionaries and grammars define it incorrectly.
Occasionally a new preposition is coined. Because 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).
Verbs.
All verbal inflection is regular. There are three tenses, all of which are in the indicative mood. The other moods are the infinitive, conditional, and jussive. No aspectual distinctions are required by the grammar, but derivational expressions of Aktionsart are common.
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).
Most verbs are inherently transitive or intransitive. As with the inherent part of speech of a root, 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):
The verbal paradigm.
The tenses have characteristic vowels. "A" indicates the present tense, "i" the past, and "o" the future.
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).
Tense.
As in English, Esperanto present tense may be used for generic statements such as "birds fly" ("la birdoj flugas").
The Esperanto future is a true tense, used whenever future time is meant. For example, in English "(I'll give it to you) when I see you" the verb "see" is in the present tense despite the time being in the future; in Esperanto, future tense is required: "(Mi donos ĝin al vi) kiam mi vidos vin".
Esperanto tense is relative. This differs from English absolute tense, where the tense is past, present, or future of the moment of speaking: In Esperanto, the tense of a subordinate verb is instead anterior or posterior to the time of the main verb. For example, "John said that he would go" is in Esperanto "Johano diris, ke li iros" (lit., "John said that he will go"); this does not mean that he will go at some point in the future from now (as "John said that he will go" means in English), but that at the time he said this, his going was still in the future.
Mood.
The conditional mood is used for such expressions as "se mi povus, mi irus" (if I could, I would go) and "se mi estus vi, mi irus" (if I were you, I'd go).
The jussive mood is used for wishing and requesting. It serves as the imperative and performs some of the functions of a subjunctive:
Aspect.
Verbal aspect is not grammatically required in Esperanto. However, aspectual distinctions may be expressed via participles (see below), and the Slavic aspectual system survives in two aktionsart affixes, perfective (often inceptive) "ek-" and imperfective "-adi." Compare,
and,
Various prepositions may also be used as aktionsart prefixes, such as "el" (out of), used to indicate that an action is performed to completion or at least to a considerable degree, also as in Slavic languages, as in,
Copula.
The verb "esti" (to be) is both the copula ("X is Y") and the existential ("there is") verb. As a copula linking two noun phrases, it causes neither to take the accusative case. Therefore, unlike the situation with other verbs, word order with "esti" can be semantically important: compare "hundoj estas personoj" (dogs are people) and "personoj estas hundoj" (people are dogs).
One sometimes sees "esti"-plus-adjective rendered as a verb: "la ĉielo estas blua" as "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.
Participles.
Participles are verbal derivatives. In Esperanto, there are six forms:
times
The participles represent aspect by retaining the vowel of the related verbal tense: i, a, o. In addition to carrying aspect, participles are the principal means of representing voice, with either nt or t following the vowel (see next section).
Adjectival participles.
The basic principle of the participles may be illustrated with the verb "fali" (to fall). Picture a cartoon character running off a cliff. Before the character falls, they are "falonta" (about to fall). As they drop, they are "falanta" (falling). After they hit the ground, they are "falinta" (fallen).
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:
Compound tense.
Compound tenses are formed with the adjectival participles plus "esti" (to be) as the auxiliary verb. The participle reflects aspect and voice, while the verb carries tense:
These are not used as often as their English equivalents. For "I "am" go"ing" 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 active synthetic forms are:
Infinitive and jussive forms are also found. There is a parallel passive paradigm. A few of these forms, notably "-intus" and "-atas", have entered common usage, but most are rare because they are more difficult to parse than periphrastic constructions.
Nominal participles.
Participles may be turned into adverbs or nouns by replacing the adjectival suffix "-a" with "-e" or "-o." This means that, in Esperanto, some nouns may be inflected for tense.
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."
Adverbial participles.
Adverbial participles are used with subjectless clauses:
Conditional and tenseless participles (unofficial).
Occasionally, the participle paradigm will be extended to include conditional participles, with the vowel "u (-unt-, -ut-)." If, for example, in our tree-chopping example, the woodsman found that the tree had been spiked and so couldn't be cut down after all, he would be "hakunta" and the tree "hakuta" (he, the one "who would chop", and the tree, the one that "would be chopped").
This can also be illustrated with the verb "prezidi" (to preside). Just after the recount of the 2000 United States presidential election:
Tense-neutral words such as "prezidento" and "studento" are officially distinct nominal roots, not derivatives of the verbs "prezidi" and "studi".
Negation.
A statement is made negative by using "ne" or one of the negative "(neni-)" correlatives. Ordinarily, only one negative word is allowed per clause:
Two negatives within a clause cancel each other out, with the result being a positive sentence.
The word "ne" comes before the word it negates:
The latter will frequently be reordered as "ne tion mi skribis" depending on the flow of information.
Questions.
"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.
Conjunctions.
Basic Esperanto conjunctions are "kaj" (both/and), "kun" (with), "aŭ" (either/or), "nek" (neither/nor), "se" (if), "ĉu" (whether/or), "sed" (but), "anstataŭ" (instead of), "krom" (besides, except for), "kiel" (like, as), "ke" (that). Like prepositions, they precede the phrase or clause they modify:
However, unlike prepositions, they allow the accusative case, as in the following example from Don Harlow:
Interjections.
Interjections may be derived from bare affixes or roots: "ek!" (get going!), from the perfective prefix; "um" (um, er), from the indefinite/undefined suffix; "fek!" (shit!), from "feki" (to defecate).
Word formation.
Esperanto derivational morphology uses a large number of lexical and grammatical affixes (prefixes and suffixes). These, along with compounding, decrease the memory load of the language, as they allow for the expansion of a relatively small number of basic roots into a large vocabulary. For example, the Esperanto root "vid-" (see) regularly corresponds to several dozen English words: "see (saw, seen), sight, blind, vision, visual, visible, nonvisual, invisible, unsightly, glance, view, vista, panorama, observant" etc., though there are also separate Esperanto roots for a couple of these concepts.
Numbers.
Numerals.
The cardinal numerals are:
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:
In such use "unu" is irregular in that it doesn't take the accusative affix "-n" in the singular, but does in the plural:
but
Additionally, when counting off, the final "u" of "unu" may be dropped, as if it were a part-of-speech suffix:
Higher numbers.
At numbers beyond the thousands, the international roots "miliono" (million) and "miliardo" (milliard) are used. Beyond this there are two systems: A "billion" in most English-speaking countries is different from a "billion" in most other countries (109 "vs." 1012 respectively; that is, a thousand million "vs." a million million). The international root "biliono" is likewise ambiguous in Esperanto, and is deprecated for this reason. An unambiguous system based on adding the Esperanto suffix "-iliono" to numerals is generally used instead, sometimes supplemented by a second suffix "-iliardo:"
Note that these forms are grammatically nouns, not numerals, and therefore cannot modify a noun directly: "mil homojn" (a thousand people [accusative]) but "milionon da homoj" (a million people [accusative]).
Compound numerals and derivatives.
Numerals are written together as one word when their values are multiplied, and separately when their values are added ("dudek" 20, "dek du" 12, "dudek du" 22). Ordinals are formed with the adjectival suffix "-a," quantities with the nominal suffix "-o," multiples with "-obl-," fractions with "‑on‑", collectives with "‑op‑", and repetitions with the root "‑foj‑".
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.
Comparisons.
Comparisons are made with the adverbial correlatives "tiel ... kiel" (as ... as), the adverbial roots "pli" (more) and "plej" (most), the antonym prefix "mal-," and the preposition "ol" (than):
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":
Word order.
Esperanto has a fairly flexible word order. However, word order does play a role in Esperanto grammar, even if a much lesser role than it does in English. For example, the negative particle "ne" generally comes before the element being negated; negating the verb has the effect of negating the entire clause (or rather, there is ambiguity between negating the verb alone and negating the clause):
However, when the entire clause is negated, the "ne" may be left till last:
The last order reflects a typical topic–comment (or theme–rheme) order: Known information, the topic under discussion, is introduced first, and what one has to say about it follows. (I went not: As for my going, there was none.) For example, yet another order, "ne iris mi", would suggest that the possibility of not having gone was under discussion, and "mi" is given as an example of one who did not go.
Compare:
The noun phrase.
Within a noun phrase, either the order "adjective–noun" or "noun–adjective" may occur, though the former is somewhat more common. 
Because of adjectival agreement, an adjective may be separated from the rest of the noun phrase without confusion, though this is only found in poetry, and then only occasionally: 
Possessive pronouns strongly favor initial position, though the opposite is well known from "Patro nia" 'Our Father' in the Paternoster. 
Less flexibility occurs with demonstratives and the article, with "demonstrative–noun" being the norm, as in English:
However, the article "la" occurs a noun phrase:
Noun–demonstrative order is used primarily for emphasis ("plumo tiu" 'that pen'). "La" occurs at the very beginning of the noun phrase except rarely in poetry.
Even less flexibility occurs with numerals, with "numeral–noun" being almost universal:
and noun–numeral being practically unheard of outside poetry.
Adjective–noun order is much freer. With simple adjectives, adjective–noun order predominates, especially if the noun is long or complex. However, a long or complex adjective typically comes after the noun, in some cases parallel to structures in English, as in the second example below:
Adjectives also normally occur after correlative nouns. Again, this is one of the situations where adjectives come after nouns in English:
Changing the word order here can change the meaning, at least with the correlative "nenio" 'nothing':
With multiple words in a phrase, the order is typically demonstrative/pronoun–numeral–(adjective/noun):
In prepositional phrases, the preposition is "required" to come at the front of the noun phrase (that is, even before the article "la"), though it is commonly replaced by turning the noun into an adverb:
Constituent order.
Constituent order "within" a clause is generally free, apart from copular clauses.
The default order is subject–verb–object, though any order may occur, with subject and object distinguished by case, and other constituents distinguished by prepositions:
The expectation of a topic–comment (theme–rheme) order apply here, so the context will influence word order: in "la katon ĉasis la hundo", the cat is the topic of the conversation, and the dog is the news; in "la hundo la katon ĉasis", the dog is the topic of the conversation, and it is the action of chasing that is the news; and in "ĉasis la hundo la katon", the action of chasing is already the topic of discussion.
Context is required to tell whether
means the dog chased a cat which was in the garden, or there, in the garden, the dog chased the cat. These may be disambiguated with
and
Of course, if it chases the cat in"to" the garden, the case of 'garden' would change:
Within copulative clauses, however, there are restrictions. Copulas are words such as "esti" 'be', "iĝi" 'become', "resti" 'remain', and "ŝajni" 'seem', for which neither noun phrase takes the accusative case. In such cases only two orders are generally found: noun-copula-predicate and, much less commonly, predicate-copula-noun.
Generally, if a characteristic of the noun is being described, the choice between the two orders is not important:
However, "la vento sovaĝa estas" is unclear, at least in writing, as it could be interpreted as 'the wild wind exists.'
When two noun phrases are linked by a copula, greater chance exists for ambiguity, at least in writing where prosody is not a cue. A demonstrative may help:
But in some cases word order is the only clue, in which case the subject comes before the predicate:
Attributive phrases and clauses.
In the sentence above, "la hundo ĉasis la katon, kiu estis en la ĝardeno" 'the dog chased the cat, which was in the garden', the relative pronoun "kiu" 'which' is restricted to a position "after" the noun 'cat'. In general, relative clauses and attributive prepositional phrases follow the noun they modify.
Attributive prepositional phrases, which are dependent on nouns, include genitives ("la libro de Johano" 'John's book') as well as "la kato en la ĝardeno" 'the cat in the garden' in the example above. Their order cannot be reversed: neither "*la de Johano libro" nor "*la en la ĝardeno kato" is possible. This behavior is more restrictive than prepositional phrases which are dependent on verbs, and which can be moved around: both "ĉasis en la ĝardeno" and "en la ĝardeno ĉasis" are acceptable for 'chased in the garden'.
Relative clauses are similar, in that they are attributive and are subject to the same word-order constraint, except that rather than being linked by a preposition, the two elements are linked by a relative pronoun such as "kiu" 'which':
Note that the noun and its adjacent relative pronoun do not agree in case. Rather, their cases depend on their relationships with their respective verbs. However, they do agree in number:
Other word orders are possible, as long as the relative pronoun remains adjacent to the noun it depends on:
Clause order.
Coordinate clauses allow flexible word order, but tend to be iconic. For example, in
the inference is that the cat fled after the dog started to chase it, not that the dog chased a cat which was already fleeing. For the latter reading, the clause order would be reversed:
This distinction is lost in subordinate clauses such as the relative clauses in the previous section:
In written English, a comma disambiguates the two readings, but both take a comma in Esperanto.
Non-relative subordinate clauses are similarly restricted. They follow the conjunction "ke" 'that', as in,
Non-Indo-European aspects.
Esperanto's vocabulary, syntax, and semantics derive predominantly from Indo-European national languages. Roots are typically Romance or Germanic in origin. The semantics shows a significant Slavic influence. What aspects do not derive directly from its source languages are generally extensions of them.
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 based on invariant morphemes, and the subsequent lack of ablaut (internal inflection of its roots), which Zamenhof himself thought would prove alien to non-Indo-European language speakers. Ablaut is an element of all the source languages; an English example is "song sing sang sung." However, the majority of words in all Indo-European languages inflect without ablaut, as "cat, cats" and "walk, walked" do in English. (This is the so-called strong–weak dichotomy.) Historically, many Indo-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", "plej", "plu" (more, most, further), "tre", "tro" (very, too much), and in the verbal morphemes "‑as", "‑anta", "‑ata"; "‑is", "‑inta", "‑ita"; "‑os", "‑onta", "‑ota"; and "‑us".
Other features often cited as being nonstandard for an Indo-European language, such as the dedicated suffixes for different parts of speech, or the "-o" suffix for singular nouns, actually do occur in Indo‑European languages such as Russian. More pertinent is the accusative plural in "-jn", which is derived through leveling of the Greek nominal–adjectival paradigm: Esperanto nominative singular "muzo (muse) vs. Greek "mousa, nominative plural "muzoj vs. Greek "mousai," and accusative singular "muzon vs. Greek "mousan." (Latin and Lithuanian had very similar setups, with in the plural and a nasal in the accusative.) Esperanto is thus "formally" similar to the non‑Indo‑European languages Hungarian and Turkish—that is, it is similar in its mechanics, but not in use. None of these proposed "non-European" elements of the original Esperanto proposal were actually taken from non-European or non-Indo-European languages, and any similarities with those languages are coincidental.
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. However, this regularization of existing grammatical forms was always found in poetry; if there has been an influence of an East Asian language, it has only been in the spread of such forms, not in their origin. Such usage is not entirely unknown in Europe: Latin has an analogous "folium viret" for "folium viride est" (the leaf is green) and "avis rubet" for "avis rubra est" (the bird is red).
Perhaps the best candidate for a "non-Indo-European" feature is the blurred distinction between root and affixe. Esperanto derivational affixes may be used as independent roots and inflect for part of speech like other roots. This occurs only sporadically in other languages of the world, Indo-European or not. For example, "ismo" has an English equivalent in "an ism", but English has no adjectival form equivalent to Esperanto "isma." For most such affixes, natural languages familiar to Europeans must use a separate lexical root.
Sample text.
The Pater noster, from the first Esperanto publication in 1887, illustrates many of the grammatical points presented above:
The morphologically complex words (see Esperanto word formation) are: