English marks plural mainly on the noun and does not change ordinary adjectives: “a new book,” “new books,” “I bought new books.” Esperanto spreads number and case across the words that directly describe a noun. Once a noun phrase is plural, its agreeing adjectives take -j; once that phrase is a direct object, the noun and those adjectives also take -n.
For the underlying noun-phrase rule before working through the diagnostics here, see adjective agreement in the accusative.
Build endings in a fixed order
The useful formula is:
root + word-class ending + J + N
For nouns, that gives libro → libroj → libron → librojn. For adjectives, it gives nova → novaj → novan → novajn. When both plural and accusative are present, j always comes before n.
| Role and number | Noun | Adjective + noun |
|---|---|---|
| singular subject | libro | nova libro |
| plural subject | libroj | novaj libroj |
| singular object | libron | novan libron |
| plural object | librojn | novajn librojn |
La nova libro alvenis hodiaŭ.
The new book arrived today.
La novaj libroj alvenis hodiaŭ.
The new books arrived today.
Mi mendis la novajn librojn hieraŭ.
I ordered the new books yesterday.
The article la is invariant. It never takes -j or -n. Agreement begins with adjective-like words and continues to the noun.
Which words agree?
Ordinary adjectives agree, including possessives and ordinal numbers because they are adjective forms.
Ni invitis niajn afablajn najbarojn al la kvartala festo.
We invited our friendly neighbors to the neighborhood party.
Ŝi relegis la unuajn tri ĉapitrojn.
She reread the first three chapters.
In niajn novajn najbarojn, all three marked words belong to one plural object phrase. In la unuajn tri ĉapitrojn, unuajn and ĉapitrojn agree, while the cardinal number tri remains unchanged.
The -u and -a table words also accept plural and accusative endings when their meanings allow them:
Kiujn fotojn vi volas konservi?
Which photos do you want to keep?
Mi forigos tiujn neklarajn fotojn.
I will remove those blurry photos.
Here kiujn and tiujn mark plural object reference. Table words ending in -o, such as kio and tio, can take -n but not normally -j: Kion vi elektis?
Direct modifiers agree; other phrases do not copy endings
Agreement applies to adjectives that directly describe the noun. A following prepositional phrase has its own internal grammar.
Mi legis la interesajn artikolojn pri klimata politiko.
I read the interesting articles about climate policy.
Interesajn agrees with object artikolojn. The phrase pri klimata politiko is governed by pri, so its words do not copy plural or accusative endings from artikolojn.
The same principle prevents learners from spreading -n across every word between the verb and the period:
Ni sendis la gravajn dokumentojn al la nova direktoro.
We sent the important documents to the new director.
Only la gravajn dokumentojn is the direct object. Al la nova direktoro is an al phrase.
Predicative adjectives: number yes, object -n no
An adjective can describe a noun through a linking or other verb rather than sit directly inside its noun phrase. Such a predicative adjective agrees in number with the noun it describes, but it does not copy the object's -n.
La proponoj estas realismaj.
The proposals are realistic.
Ni opinias la proponojn realismaj.
We consider the proposals realistic.
In the second sentence, la proponojn is the plural object. Realismaj states the assessment made of the proposals. It takes -j because multiple proposals are described, but no -n because it is not a direct modifier inside la proponojn.
Compare the near-neighbor:
Ni subtenas la realismajn proponojn.
We support the realistic proposals.
Now realismajn directly identifies which proposals are supported, so it belongs inside the plural accusative noun phrase and takes -jn. This distinction is semantic as well as formal: opinias ... realismaj assigns an assessment, while la realismajn proponojn selects proposals already described as realistic.
Agreement after esti
A predicative adjective agrees with the subject in number:
La du ĉambroj estas sufiĉe grandaj.
The two rooms are large enough.
English large remains unchanged, so English speakers often produce la ĉambroj estas granda. Esperanto treats grandaj as describing the plural rooms and requires -j.
A predicative noun, however, follows meaning rather than mechanical copying. If several people are members of the same singular category, the natural predicate is often plural because there are several instances:
Miaj gepatroj estas instruistoj.
My parents are teachers.
This page concentrates on adjective–noun agreement; predicate noun number still depends on what the noun phrase denotes.
Numbers do not block plural agreement
After cardinal numbers above one, the count noun is plural. The number itself stays invariant.
Sur la tablo kuŝas kvar puraj tasoj.
Four clean cups are lying on the table.
Bonvolu alporti kvar purajn tasojn.
Please bring four clean cups.
The first noun phrase is the subject: puraj tasoj. The second is the object: purajn tasojn. The unchanged kvar does not remove plural -j from the noun or adjective.
Quantifiers with da follow a different structure. In multe da freŝa pano, pano names the substance measured and does not agree with multe. Do not generalize the ordinary adjective agreement rule across da.
Coordinated descriptions and ellipsis
When two adjectives both directly describe the same object noun, both carry its agreement endings.
Ni bezonas klarajn kaj mallongajn instrukciojn.
We need clear and short instructions.
When a repeated noun is omitted, the remaining adjective can carry the endings that identify the missing noun's number and role.
Mi prenis la bluajn tasojn, ne la verdajn.
I took the blue cups, not the green ones.
Verdajn stands for verdajn tasojn. Its endings are not decorative: they show that the omitted noun is plural and that the phrase contrasts with the object of prenis.
A repair routine for long noun phrases
Start at the head noun, not at the first visible error.
- Decide whether the head noun is singular or plural.
- Decide whether the whole noun phrase is an object.
- Build the head ending: -o, -oj, -on, -ojn.
- Find every direct adjective-like modifier.
- Give each modifier matching -a, -aj, -an, -ajn.
- Leave la, cardinal numbers, adverbs, and prepositional phrases unchanged.
Ĉu vi jam legis tiujn du tre longajn retmesaĝojn?
Have you already read those two very long emails?
The head is plural object retmesaĝojn. Demonstrative tiujn and adjective longajn agree. Du is invariant; tre is an adverb modifying longajn and is also invariant.
Norm and usage status
Plural and accusative agreement on direct adjective modifiers is foundational Esperanto grammar in every register. Poetic order and noun ellipsis preserve the endings that remain. Rapid pronunciation may make final consonant clusters challenging, but writing them and articulating them clearly is not an optional formal style. Predicative adjectives without object -n are also part of the norm, not an exception invented to simplify speech.
Common Mistakes
Marking plural only on the noun
❌ La ruĝa aŭtoj estas niaj.
Incorrect — ruĝa directly describes a plural noun.
✅ La ruĝaj aŭtoj estas niaj.
The red cars are ours.
Marking accusative only on the noun
❌ Mi aĉetis du bela librojn.
Incorrect — the adjective lacks plural accusative agreement.
✅ Mi aĉetis du belajn librojn.
I bought two beautiful books.
Putting n before j
❌ Ni vizitis la malnovanj domonj.
Incorrect ending order — plural -j must precede accusative -n.
✅ Ni vizitis la malnovajn domojn.
We visited the old houses.
Copying object -n onto a predicative adjective
❌ Ni opinias ilin tre utilajn.
Incorrect — the predicative assessment of ilin should agree only in number.
✅ Ni opinias ilin tre utilaj.
We consider them very useful.
Forgetting agreement on a possessive
❌ Ŝi invitis mia novaj kolegoj.
Incorrect — the whole phrase is a plural object.
✅ Ŝi invitis miajn novajn kolegojn.
She invited my new colleagues.
Key Takeaways
Direct adjective-like modifiers share the noun's plural -j and object -n, always in the order -jn. Articles, cardinal numbers, adverbs, and prepositional phrases stay invariant. Predicative adjectives agree in number but do not copy an object's -n. Repair the analysis from the head noun outward instead of fixing only the most visible ending.
Related Topics
- Adjective Agreement in NumberA1 — Learn why Esperanto adjectives take -j when they describe plural people or things, in both noun phrases and predicates.
- 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.
- Singular and Plural NounsA1 — How Esperanto builds singular, plural, and accusative noun forms from a stable root using -o, -j, and -n.
- Direct ObjectsA1 — Learn which Esperanto verb complements are direct objects, how -n marks them, and how object marking remains stable when word order changes.
- Demonstrative DeterminationA1 — How tiu, ĉi tiu, and tia identify an individual or a type without combining with la.