Esperanto adjectives end in -a. When an adjective describes more than one person or thing, it adds the plural ending -j: nova becomes novaj. This agreement is not decorative repetition. It shows which noun, pronoun, or understood referent the description belongs to.
The basic pattern: -a and -aj
The foundational rule is simple: a singular referent takes an adjective in -a, while a plural referent takes -aj. The noun normally shows the same number contrast with -o/-oj.
| Meaning | Adjective | Noun phrase |
|---|---|---|
| singular | nova | nova telefono |
| plural | novaj | novaj telefonoj |
Mi bezonas novan telefonon, ĉar la mia ne plu funkcias.
I need a new phone because mine no longer works.
Ĉu vi vidis la novajn fotojn de nia vojaĝo?
Did you see the new photos from our trip?
The -j is pronounced, so nova and novaj are distinct in speech as well as writing. English normally leaves an adjective unchanged—“a new photo,” “new photos”—which makes omission of -j one of the most persistent transfer errors.
Agreement inside the noun phrase
An adjective used directly with a noun is attributive. It belongs inside the noun phrase and agrees with the referent of that phrase, wherever the adjective is placed. A following adjective is not exempt from agreement.
Sur la tablo kuŝas du malfermitaj leteroj.
Two open letters are lying on the table.
Ni elektis ĉambrojn grandajn kaj helajn.
We chose rooms that were large and bright.
The head noun controls the agreement. Do not match an adjective with the nearest visible word or with an idea hidden inside the adjective. In krajonaj notoj (“pencil notes” or “notes in pencil”), krajonaj is plural because it describes plural notoj, not because there are several pencils.
Ŝi lasis krajonajn notojn ĉe la fino de la raporto.
She left pencil notes at the end of the report.
English also lets one noun modify another: “winter holidays,” “university libraries.” Esperanto normally turns that first concept into an adjective, and that adjective then agrees like any other.
La universitataj bibliotekoj restas malfermitaj ĝis la oka.
The university libraries stay open until eight.
Here universitataj describes bibliotekoj, and malfermitaj describes the same plural libraries through restas. Both therefore take -j. See adjectives and the -a ending for the productive formation of such adjectives.
Predicative adjectives agree too
An adjective after esti (“to be”), fariĝi (“to become”), resti (“to remain”), or ŝajni (“to seem”) is predicative: it makes a statement about the subject. It still agrees in number, even though it is no longer next to the noun.
La kafejo estas plena, sed la restoracio estas preskaŭ malplena.
The café is full, but the restaurant is almost empty.
Post la longa vojaĝo la infanoj estis lacaj kaj malsataj.
After the long journey, the children were tired and hungry.
La fenestroj ne estas puraj; mi lavos ilin morgaŭ.
The windows are not clean; I'll wash them tomorrow.
Agreement follows meaning rather than distance. In the second example, lacaj and malsataj refer back across the verb to plural la infanoj. The full distinction between these two uses is developed in Attributive and Predicative Adjectives.
Agreement with pronouns
With a pronoun, choose singular or plural according to whom the pronoun represents. Mi, li, ŝi, and singular ĝi take singular adjectives; ni and ili take plural adjectives. Vi can address one person or several, so the adjective reveals the intended number.
Mi estas preta. Ĉu ankaŭ vi estas preta?
I'm ready. Are you ready too? (addressing one person)
Ni estas pretaj. Ĉu ankaŭ vi estas pretaj?
We're ready. Are you all ready too? (addressing several people)
Ili ne aspektas kontentaj pri la decido.
They don't look satisfied with the decision.
This is a place where translating the English surface form is especially unreliable: English “ready” never changes, while Esperanto preta/pretaj distinguishes one addressee from several.
One adjective describing several referents
If one adjective describes two or more coordinated people or things together, its meaning is plural and it takes -j, even when each noun is singular.
La kuirejo kaj la salono estas tre helaj.
The kitchen and the living room are very bright.
Marta kaj ŝia frato alvenis malsekaj pro la pluvo.
Marta and her brother arrived wet from the rain.
In careful standard usage, this semantic agreement is required: the adjective describes the combined set, not merely the closest noun. Word order does not alter the relationship.
When the noun is omitted
Esperanto often omits a noun when the context makes it recoverable. The adjective remains an adjective and keeps the number of the understood noun. English may use “the red ones”; Esperanto can simply say la ruĝaj.
La nigraj ŝuoj estas tro formalaj; mi portos la brunajn.
The black shoes are too formal; I'll wear the brown ones.
Kiujn biletojn vi aĉetis? — La plej malmultekostajn.
Which tickets did you buy? — The cheapest ones.
The second example also has -n because the understood tickets are the direct object. The order of endings is fixed: adjective ending -a, then plural -j, then accusative -n: malmultekost-a-j-n. Number agreement remains the same system; Adjective Agreement in the Accusative explains the case ending.
Meaning can override mechanical matching
Most phrases show the same number on adjective and noun. There is, however, an important semantic pattern: a singular adjective can pick out one member of a larger plural set.
Sur la tablo kuŝis unu ruĝa kaj tri bluaj krajonoj.
One red pencil and three blue pencils were lying on the table.
Mi bezonas verdan kaj ruĝan krajonojn por la mapo.
I need a green pencil and a red pencil for the map.
In these attested standard patterns, ruĝa, verd-an, and ruĝ-an are singular because each description applies to one pencil; the plural noun is shared to avoid repetition. Compare verdajn kaj ruĝajn krajonojn, which naturally presents plural green pencils and plural red pencils, or at least two plural categories. This is not random failure of agreement: the endings reveal each adjective's semantic scope.
For beginners, the clearest choice is often to repeat the noun—verdan krajonon kaj ruĝan krajonon—until the compact pattern feels natural.
Common Mistakes
Leaving the adjective singular before a plural noun
❌ Mi aĉetis freŝa pomojn.
Incorrect — freŝa lacks plural agreement.
✅ Mi aĉetis freŝajn pomojn.
I bought fresh apples.
Because the whole phrase is also a direct object, freŝajn needs both -j and -n.
Forgetting agreement after a linking verb
❌ La gastoj jam estas preta.
Incorrect — preta does not agree with the plural subject.
✅ La gastoj jam estas pretaj.
The guests are already ready.
Predicative position changes the adjective's function, not its number.
Matching only the nearest noun
❌ La seĝo kaj la tablo estas malnova.
Incorrect — malnova describes both coordinated nouns.
✅ La seĝo kaj la tablo estas malnovaj.
The chair and the table are old.
Copying an English noun modifier
❌ La universitato bibliotekoj estas fermitaj hodiaŭ.
Incorrect — Esperanto does not normally use universitato as an English-style noun modifier.
✅ La universitataj bibliotekoj estas fermitaj hodiaŭ.
The university libraries are closed today.
Key Takeaways
- -a marks an adjective; add -j when its referent is plural.
- Agreement works both inside a noun phrase and across a linking verb.
- Follow the adjective's actual referent, not merely the closest word.
- An adjective with an omitted noun still shows the understood noun's number.
- Singular adjectives before a shared plural noun are possible when each adjective semantically selects one member of the set.
Related Topics
- Adjectives and the -A EndingA1 — How the productive -a ending creates describing words and how adjectives agree, modify nouns, and function after esti.
- Adjective Agreement in the AccusativeA1 — Learn when Esperanto adjectives copy the accusative -n, how -ajn is built, and why predicative adjectives normally remain without -n.
- Attributive and Predicative AdjectivesA2 — Distinguish adjectives inside noun phrases from adjectives that assert a subject's or object's state, and choose agreement endings accordingly.
- Singular and Plural NounsA1 — How Esperanto builds singular, plural, and accusative noun forms from a stable root using -o, -j, and -n.
- Substantivized AdjectivesA1 — Distinguish adjectives used with an omitted noun from true nouns formed from the same root, and mark number and case correctly in both patterns.
- Missing Plural and Accusative AgreementA2 — Make nouns and their direct modifiers agree in plural -j and accusative -n without overmarking invariant words or predicates.