# 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.
| Description | Word | Meaning |
| Root meaning "laugh" | rid | No meaning |
| Adding infinitive verb ending -i | ridi | To laugh |
| Adding adjective ending -a | rida | Laughing (for example, "a laughing hyena" is rida hieno) |
| Adding adjective ending -a and -ind affix meaning "worthy of" | ridinda | Laughable (worthy of laughs) |
| Adding noun ending -o | rido | (A) laugh |
| Adding noun ending -o and -ad affix meaning "repeated action" | ridado | Laughter (repeated laughs) |
| Root meaning "mock/tease" | mok | No meaning |
| Combining root for "mock" with root for "laugh", then adding infinitive verb ending -i | mokridi (pri) | To (mockingly) laugh (at) |
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 (hundo means "a dog"). The definite particle is la (la hundo means "the dog").

### Plural

Singular nouns end in -o (or -on). The plural is formed by adding -j (forming -oj or -ojn).
| Esperanto | English |
| hundo | (a) dog |
| hundoj | (some) dogs |
| la hundo | the dog |
| la hundoj | the dogs |

### 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.
| Esperanto | English |
| Hundo pelas katon. | A dog is chasing a cat. |
| Katon pelas hundo. | A dog is chasing a cat. |
| Hundo katon pelas. | A dog is chasing a cat. |
| Katon hundo pelas. | A dog is chasing a cat. |
| Pelas hundo katon. | A dog is chasing a cat. |
| Pelas katon hundo. | A dog is chasing a cat. |
With the plural, the same rules apply.
| Esperanto | English |
| Hundoj pelas katojn. | Dogs chase cats. |
| Katojn pelas hundoj. | Dogs chase cats. |
| Hundoj katojn pelas. | Dogs chase cats. |
| Katojn hundoj pelas. | Dogs chase cats. |
| Pelas hundoj katojn. | Dogs chase cats. |
| Pelas katojn hundoj. | Dogs chase cats. |

### Verb nouns

Verb nouns do not exist in English, with the exception of the active present (usually by adding -er: "to view" → "the viewer"), the passive present (usually by adding -ee: "to view" → "the viewee") and the passive past (usually by adding -ed: "to view" → "the viewed"). Esperanto has these forms and more.
However, Esperanto is much more specific than English. Skribanto means "writer", but it specifically means "person who is writing now", not "person who writes professionally" (which would be skribisto).

#### Active verb nouns

| | Meaning | Esperanto | English |
| -into | One who was ...ing | Skribinto | One who was writing |
| -anto | One who is ...ing | Skribanto | One who is writing |
| -onto | One who will be ...ing | Skribonto | One who will be writing |

#### Passive verb nouns

| | Meaning | Esperanto | English |
| -ito | One who was ...ed | Amito | One who was loved |
| -ato | One who is ...ed | Amato | One who is loved |
| -oto | One who will be ...ed | Amoto | One who will be loved |

## 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.
| Esperanto | English | Case |
| granda hundo | (a) big dog | Subjective |
| grandaj hundoj | (some) big dogs | Subjective |
| grandan hundon | (a) big dog | Accusative |
| grandajn hundojn | (some) big dogs | Accusative |
The adjective does not need to appear before, or even next to, the noun it is modifying.
| Esperanto | English |
| La hundo havas ruĝan pilkon. | The dog has a red ball. |
| La hundo havas pilkon ruĝan. | The dog has a red ball. |
| La hundo pilkon havas ruĝan. | The dog has a red ball. |

### Verb adjectives

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

### Active verb adjectives

| | Meaning | Esperanto | English |
| -inta | was ...ing | Paginta viro | A man who was paying |
| -anta | ...ing | Paganta viro | Paying man |
| -onta | will be ...ing | Pagonta viro | A man who will be paying |

#### Passive verb adjectives

| | Meaning | Esperanto | English |
| -ita | ...ed | Pagita viro | Paid man |
| -ata | being ...ed | Pagata viro | A man being paid |
| -ota | will be ...ed | Pagota viro | A man who will be paid |

### Agreement

As adjectives, they must match (or agree with) the noun they are modifying.
| Esperanto | English |
| La libro estas skribata. | The book is being written. |
| La libroj estas skribataj. | The books are being written. |

### 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 pli (more) or malpli (less):
* pli bela - more beautiful
* malpli bela - less beautiful
* pli bona - better
* pli malbona - worse
* pli saĝa - wiser
Superlatives are formed using plej (most) or malplej (least):
* plej bela - most beautiful
* malplej bela - least beautiful
* plej bona - best
* plej malbona - worst
* plej saĝa - 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.
| Subjective | Subjective | Accusative | Accusative |
| Esperanto | English | Esperanto | English |
| Mi | I | Min | Me |
| Vi | You (singular and plural) | Vin | You (singular and plural) |
| Li | He | Lin | Him |
| Ŝi | She | Ŝin | Her |
| Ĝi | It | Ĝin | It |
| Ni | We | Nin | Us |
| Ili | They | Ilin | Them |
| Oni | One | Onin | One |
| Ci | Thou | Cin | Thee |
Oni means "one" in the sense of "how does one do that?" ("Kiel oni faras tion?"). It does not mean the number one (1).

### Possessive

Possessive pronouns are simply adjectives formed from the pronouns by adding -a.
| Esperanto | English |
| Mia | My/mine |
| Via | Your/yours |
| Lia | His |
| Ŝia | Her/hers |
| Ĝia | Its |
| Nia | Our/ours |
| Ilia | Their/theirs |
| Onia | One's |
| Cia | Thy/thine |
They follow the same rules as other adjectives, and must agree with the plurality and subjective/accusative case of the noun they modify.
| Esperanto | English |
| Mia hundo pelas vian katon. | My dog is chasing your cat. |
| La bluaj pilkoj estas liaj (pilkoj). | The blue balls are his (balls). |
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 si (with accusative case sin). 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).
| Esperanto | English | Notes |
| Li amas sin. | He loves himself. | If you said "Li amas lin.", you would be saying "He loves him (some other guy)". |
| Ŝi lavas siajn manojn. | She washes her hands (her own hands). | If you said "Ŝi lavas ŝiajn manojn.", you would be saying "She washes her hands (some other woman's hands)". |

## Numbers

The cardinal numbers do not have a grammatical ending. Other than unu, du, tri and naŭ (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.
| Esperanto | English |
| Nul | Zero |
| Unu | One |
| Du | Two |
| Tri | Three |
| Kvar | Four |
| Kvin | Five |
| Ses | Six |
| Sep | Seven |
| Ok | Eight |
| Naŭ | Nine |
| Dek | Ten |
| Cent | (One) hundred |
| Mil | (One) thousand |
The remaining numbers are formed by combination of these bases. Concatenating numbers together, as in naǔcent ("nine hundred"), implies multiplication, otherwise addition is implied. For example 1984 is mil naŭcent okdek kvar.
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: Iu skribis unu unuon, kaj du kvinojn.

### 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.
| Esperanto | English | Notes |
| Unua | First | |
| Dua | Second | |
| Dudek-unua | Twenty-first | With compound numbers, a hyphen must be used. |
As in English, they can be abbreviated. This is done by replacing the word for the cardinal number with the number: unua → 1a. Because they are still adjectives, agreement is necessary: unuan → 1an, unuaj → 1aj.

## Adverbs

Adverbs are formed from roots with the ending -e.
| Esperanto | English |
| Bone | Well |
| Rapide | Quickly |
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 (hodiaŭ → "today"), others as adverbs and conjunctions (kvazaŭ → "as if, as though"), others as adverbs and adjectives (ambaŭ → "both"), others as adverbs and prepositions (ĉirkaŭ → "around"), others as adverbs and pronouns (pli → "more"). They generally have the ending -aŭ (the "indeterminate part-of-speech" grammatical ending), but not always.
| Esperanto | English |
| eĉ | even |
| hodiaŭ | today |
| iom | a little, rather, some, somewhat, to some extent |
| ĵus | just, just now |
| nun | now |
| nur | only |
| pli | more |
| plu | further, more |
| tro | overly, too much |
| tuj | immediately |
It is always legal to add -e to the end of these pseudo-adverbs to make them true adverbs (pli → plie), but this is rarely done for most of them.
Note
It is also legal to add other grammatical endings (nun → nuno, nuna).

## Verbs

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

### Infinitive

The infinitive ending is -i.
| Esperanto | English |
| Esti aŭ ne esti. | To be or not to be. |
| Mi volas skribi librojn. | I want to write books. |

### Imperative

The imperative ending is -u. It is used for giving direct commands (Go!) or for expressing our will (Let's...).
| Esperanto | English |
| Estu! | Do it! |
| Ne skribu librojn. | Don't write books. |
| Li skribu multajn librojn! | Let him write many books/May he write many books! |
| Ni iru al la kinejo. | Let's go to the cinema. |
| Mi iru tiam ĉi. | I should go now. |

### 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.
| Esperanto | English |
| Mi skribas librojn. | I write books. |
| Mi skribis librojn. | I wrote books. |
| Mi skribos librojn. | I will write books. |

### Conditional

The conditional ending is -us; as in English it is also used as a polite way to express a wish or request.
| Esperanto | English |
| Se mi povus, mi skribus librojn. | If I could, I would write books. |
| Se mi estus vi, mi skribus librojn. | If I were you, I would write books. |
| Ĉu mi povus havi tason da teo? | Could I have a cup of tea? |

### Participles

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

#### Active participles

| | estas | estis | estos |
| -inta (action recently completed) | estas skribinta (has written) | estis skribinta (had written) | estos skribinta (will have written) |
| -anta (action still ongoing) | estas skribanta (is writing) | estis skribanta (was writing) | estos skribanta (will be writing) |
| -onta (action soon to begin) | estas skribonta (is going to write) | estis skribonta (was about to write) | estos skribonta (will be about to write) |
As adjectives, they must agree in case and number with the noun they are modifying, which is the subject of the active participle phrase.
| Esperanto | English |
| Mi estas skribinta librojn. | I have written books. |
| Ni estis skribontaj libron. | We were about to write a book. |
| Vi estos skribanta libron. | You (singular) will be writing a book. |
| Vi estos skribantaj libron. | You (plural) will be writing a book. |

#### Passive participles

Passive participles can be formed from transitive verbs and are used for the passive voice.
| | esti | estu | estus |
| -ita (action recently completed) having been | esti skribita (to be (in the state of) having been written) (to have been written) | estu skribita (be (in the state of) having been written) (be written) | estus skribita (would be (in the state of) having been written) (would have been written) |
| -ata (action still on-going) being | esti skribata (to be (being) written) | estu skribata (be (being) written) | estus skribata (would be (being) written) |
| -ota (action soon to begin) about/going to be | esti skribota (to be about (going) to be written) | estu skribota (be about (going) to be written) | estus skribota (would be about (going) to be written) |
| | estas | estis | estos |
| -ita (action recently completed) having been | estas skribita (is (in the state of) having been written) (has been written) | estis skribita (was (in the state of) having been written) (had been written) | estos skribita (will be (in the state of) having been written) (will have been written) |
| -ata (action still on-going) being | estas skribata (is (being) written) | estis skribata (was (being) written) | estos skribata (will be (being) written) |
| -ota (action soon to begin) about/going to be | estas skribota (is about (going) to be written) | estis skribota (was about (going) to be written) | estos skribota (will be about (going) to be written) |
As adjectives, they must agree in case and number with the noun they are modifying, which is the subject of the passive participle phrase.
| Esperanto | English |
| La libro estas skribata. | The book is being written. |
| La libroj estas skribataj. | The books are being written. |
The direct object of sentences in passive voice is denoted by de after the participle:
| Esperanto | English |
| La libro estas skribata de mi. | The book is being written by me. |

## Conjunctions

Conjunctions do not have a grammatical ending. Other than ĉu ("whether/or"), se ("if") and ke ("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.
| Esperanto | English | Examples |
| ankoraŭ | still, yet | |
| aŭ | or | |
| ĉu | whether | |
| kaj | and | |
| ke | that | |
| krom | besides, in addition to | |
| se | if | |
| sed | but | |
| aŭ ... aŭ ... | either... or ... | |
| kaj ... kaj ... | both... and ... | eo: La viro kaj marŝas kaj kuras. en: The man both walks and runs. eo: La ĉevalo estas kaj granda kaj forta. en: The horse is both large and strong. eo: La knabo havas kaj rozojn kaj violojn. en: The boy has both roses and violets. eo: Kaj la knabo kaj la viro estas altaj. en: Both the boy and the man are tall. |
| nek ... nek ... | neither ... nor ... | eo: Ili nek marŝas nek kuras. en: They neither walk nor run. eo: La viro havas nek domon nek ĝardenon. en: The man has neither a house nor a garden. eo: Nek la rozo nek la violo estas verda. en: Neither the rose nor the violet is green. |

## Comparatives

Comparatives are formed by adjectives and adverbs.
| Esperanto | English | Examples |
| pli ... ol ... | more ... than ... | eo: Lakto estas pli nutra ol vino. en: Milk is more nutritious than wine. |
| malpli ... ol ... | less ... than ... | eo: Vino estas malpli nutra ol lakto. en: Wine is less nutritious than milk. |
| tiel ... kiel ... | as ... as ... | eo: Vi estas tiel forta, kiel mi. en: You are as strong as I. |
| tia ... kia ... | such ... as ... | eo: Tia domo, kia tiu, estas malofta. en: Such a house as that is rare. |
| sama ... kia ... | the same (kind of thing) ... as ... | eo: Mia bastono estas tia sama, kia la via. en: My stick is the same as yours. |
| sama ... kiel ... | the same (way or method) ... as ... | eo: Ĝia uzado estas tia sama, kiel en la aliaj lingvoj. en: Its use is the same as in the other languages. eo: Vi ĉiam laboradas al tiu sama celo, kiel mi. en: You are always working towards that same end (aim) as I. |

## The Time of Day

Ordinal numbers (unua, dua) are used for the hour of the day, with horo expressed or understood. The minutes are expressed by cardinal numbers (unu, du). In questions, as well as using kiam, the adjective kioma (from kiom, how much) can be used:
| Esperanto | English |
| Kiam vi alvenos? | When will you arrive? |
| Kioma horo estas? | What hour (what o'clock, what time) is it? |
| Je kioma horo vi venos? | At what time (what o'clock) will you come? |
| Estas la dua horo. | It is two o'clock (it is the second hour). |
| Estas la tria kaj kvin minutoj. | It is five minutes past three. |
| Ni iris je la sesa kaj duono. | We went at half past six. |
| Estas la oka kaj kvardek kvin. | It is eight forty-five. |
| Estas unu kvarono antaŭ la naŭa. | It is a quarter to nine. |
| Estas dudek minutoj antaŭ la deka. | It is twenty minutes to ten. |