Esperanto/Appendix/Summary of grammar

Structure
Esperanto words are formed by taking one or more roots, modifiying them with one or more affixes, then adding grammatical endings.

See the table of word endings and table of affixes for more word synthesis options.

Nouns
All words ending in -o, -oj, -on or -ojn are nouns.

By themselves, nouns are indefinite ( means "a dog"). The definite particle is ( means "the dog").

Plural
Singular nouns end in -o (or -on). The plural is formed by adding -j (forming -oj or -ojn).

Accusative case
When a noun is the object of a verb phrase, -n is added. This allows variable word order. In the following example, all of the Esperanto sentences mean the same thing.

With the plural, the same rules apply.

Verb nouns
Verb nouns do not exist in English, with the exception of the active present (usually by adding -er: "to view" &rarr; "the viewer"), the passive present (usually by adding -ee: "to view" &rarr; "the viewee") and the passive past (usually by adding -ed: "to view" &rarr; "the viewed"). Esperanto has these forms and more.

However, Esperanto is much more specific than English. means "writer", but it specifically means "person who is writing now", not "person who writes professionally" (which would be ).

Adjectives
All words ending in -a, -aj, -an or -ajn are adjectives.

The ending modifiers are the same as for nouns. The modifiers used are determined by the noun being modified.

The adjective does not need to appear before, or even next to, the noun it is modifying.

Verb adjectives
Verb adjectives are called participles. English has two participle forms: present (usually by adding -ing: "to boil" &rarr; "boiling water"); and past (usually by adding -ed: "to boil" &rarr; "boiled water"). Esperanto has these forms and more.

However, Esperanto is much more specific than English. English does not encode whether the adjective is active or passive --- "boiling water" says that the water is being boiled (passive), but "writing person" says that the person is doing the writing (active). If you wanted to express a passive form of writing, you would instead say the "letter being written". Attempting to express an active form of boiling would produce "boiling person", which would most likely be understood as an idiom (such as "extremely angry person") since it does not culturally make sense otherwise.

Agreement
As adjectives, they must match (or agree with) the noun they are modifying.

Dangling
In any English discussion of participles, the question of dangling participles may arise.

The first thing to realize is that English has a dangling modifier problem, participles just make it a little more obvious. Esperanto does not have this problem usually because of the -n marker.

So in English we might say "I saw a book looking through the window". Grammatically, the book is looking so the participle is dangling (or attached to the wrong noun).

In Esperanto one would say "Mi vidis libron vidanta tra la fenestro." Without the -n, "mi" is the noun that "vidanta" is modifying. If we wanted to say that the book was looking we would say "Mi vidis libron vidantan tra la fenestro."

Why does this matter?
"Mi vidis hundon vidanta tra la fenestro." I looked through the window and saw a dog.

"Mi vidis hundon vidantan tra la fenestro." I saw a dog, and that dog was looking through the window.

Comparatives and Superlatives
Comparatives are formed using (more) or  (less):
 * - more beautiful
 * - less beautiful
 * - better
 * - worse
 * - wiser

Superlatives are formed using (most) or  (least):
 * - most beautiful
 * - least beautiful
 * - best
 * - worst
 * - wisest

Pronouns
Pronouns do not have a grammatical ending. They all end in -i, which is the infinitive verb ending. However, this does not cause confusion, because there are only ten pronouns, so they are easy to identify.

As with nouns, pronouns have an accusative case formed by adding -n.

means "one" in the sense of "how does one do that?" (""). It does not mean the number one (1).

Possessive
Possessive pronouns are simply adjectives formed from the pronouns by adding -a.

They follow the same rules as other adjectives, and must agree with the plurality and subjective/accusative case of the noun they modify.

Note that certain copula verbs such as esti (to be) and ŝajni (to seem) do not take the accusative; the noun forms and modifying adjectives that follow such verbs are grammatically subjective-completion elements, not objects.

Reflexive
The reflexive pronoun is (with accusative case ). It has a possessive form like any other pronoun (by adding -a, which then has to agree in gender and case with the noun it is modifying).

Numbers
The cardinal numbers do not have a grammatical ending. Other than, , and  (1, 2, 3 and 9), their endings cannot be confused with other grammatical endings. For the four that do, this does not cause confusion, because there are only four of them, so they are easy to identify.

The remaining numbers are formed by combination of these bases. Concatenating numbers together, as in ("nine hundred"), implies multiplication, otherwise addition is implied. For example 1984 is.

Note that the cardinal numbers only refer to the idea of the numbers, not specific instances; for that you use the noun form (with -o, and normal noun rules). If you wanted to say someone wrote one instance of the number one, and two instances of the number five, you would say:

Ordinals
Ordinal numbers are adjectives, formed with -a. They follow the same rules as other adjectives, and must agree with the plurality and subjective/accusative case of the noun they modify.

As in English, they can be abbreviated. This is done by replacing the word for the cardinal number with the number: &rarr;. Because they are still adjectives, agreement is necessary: &rarr;,  &rarr;.

Adverbs
Adverbs are formed from roots with the ending -e.

Not all adverbs end with -e because not all adverbs are formed from root words. There is a small subset of words that can function as adverbs, but are not "pure" adverbs, and often can function as other parts of speech. Some can function as both adverbs and nouns ( &rarr; "today"), others as adverbs and conjunctions ( &rarr; "as if, as though"), others as adverbs and adjectives ( &rarr; "both"), others as adverbs and prepositions ( &rarr; "around"), others as adverbs and pronouns ( &rarr; "more"). They generally have the ending -aŭ (the "indeterminate part-of-speech" grammatical ending), but not always.

It is always legal to add -e to the end of these pseudo-adverbs to make them true adverbs ( &rarr; ), but this is rarely done for most of them.

Verbs
There are no irregular verbs. All conjugations are formed by adding the right ending to the root.

Infinitive
The infinitive ending is -i.

Imperative
The imperative ending is -u. It is used for giving direct commands (Go!) or for expressing our will (Let's...).

Tenses
The present tense ending is -as. The past tense ending is -is. The future tense ending is -os. There is no agreement with number or gender of either subject or object.

Conditional
The conditional ending is -us; as in English it is also used as a polite way to express a wish or request.

Participles
Participles are adjectives formed from verbs. There are two types: the active and the passive.

Active participles
As adjectives, they must agree in case and number with the noun they are modifying, which is the subject of the active participle phrase.

Passive participles
Passive participles can be formed from transitive verbs and are used for the passive voice.

As adjectives, they must agree in case and number with the noun they are modifying, which is the subject of the passive participle phrase.

The direct object of sentences in passive voice is denoted by  after the participle:

Conjunctions
Conjunctions do not have a grammatical ending. Other than ("whether/or"),  ("if") and  ("that"), their endings cannot be confused with other grammatical endings. For those that can, this does not cause confusion, because there are only a small number of them, so they are easy to identify.

Comparatives
Comparatives are formed by adjectives and adverbs.

The Time of Day
Ordinal numbers are used for the hour of the day, with horo expressed or understood. The minutes are expressed by cardinal numbers. In questions, as well as using kiam, the adjective kioma (from kiom, how much) can be used: