A copular clause links a subject to a description or identity rather than directing an action at an object. Esperanto usually uses esti “to be”: La ĉambro estas hela. The expression after the copula is a predicative complement, not a direct object, so it does not take accusative -n.
The core pattern
The neutral structure is subject + esti + predicative complement:
La nova kafejo estas trankvila.
The new café is quiet.
Mia onklino estas arkitekto.
My aunt is an architect.
In the first sentence, trankvila attributes a property to the café. In the second, arkitekto classifies the aunt by profession. Neither complement is something acted upon, so neither is an object.
The verb carries tense and mood normally:
La strato estis preskaŭ malplena hieraŭ vespere.
The street was almost empty yesterday evening.
La nova retejo estos preta antaŭ vendredo.
The new website will be ready before Friday.
Adjective complements: agreement without accusative
A predicative adjective agrees with a noun subject in number:
La fenestro estas malfermita, sed la pordoj estas fermitaj.
The window is open, but the doors are closed.
Malfermita is singular with fenestro; fermitaj is plural with pordoj. Case is different: the subject is non-accusative, and so is its description. Even in a question or marked order, the adjective does not take -n.
Kiaj estis la rezultoj?
What were the results like?
Tre pozitivaj estis la unuaj reagoj.
The initial reactions were very positive.
The adjective-first order is marked and foregrounds the evaluation tre pozitivaj. Neutral prose would normally say La unuaj reagoj estis tre pozitivaj.
Esperanto does not divide English be between permanent and temporary forms. Both a lasting trait and a passing condition use esti:
Lea estas pacienca, sed hodiaŭ ŝi estas laca.
Lea is patient, but today she is tired.
Time expressions and context distinguish the readings. There is no separate Esperanto equivalent of the Spanish ser/estar distinction.
Noun complements: category versus identity
An unmarked noun after esti often assigns the subject to a category, occupation, or role. Esperanto has no indefinite article:
Karim estas kuracisto en la urba hospitalo.
Karim is a doctor at the city hospital.
Tiuj konstruaĵoj iam estis magazenoj.
Those buildings were once warehouses.
Use la when the complement identifies a particular, recoverable individual rather than merely naming a category:
Karim estas la kuracisto, kiu telefonis al vi hieraŭ.
Karim is the doctor who called you yesterday.
Compare Li estas instruisto “He is a teacher” with Li estas la instruisto de mia filo “He is my son's teacher.” The article difference is about definiteness, not about the copula itself.
Noun complements also remain without -n:
— Ĉu Nora estas la nova kasisto? — Ne, ŝi estas la nova sekretario.
— Is Nora the new treasurer? — No, she is the new secretary.
Profession nouns in Esperanto are not forced to match natural sex. A woman can be sekretario; sekretariino explicitly marks female sex when relevant.
Identity is not always logically reversible
Both sides of esti may be unmarked noun phrases, so order and definiteness can carry essential meaning.
Leono estas besto.
A lion is an animal.
Besto estas leono.
An animal is a lion.
The first is a valid category statement; the second wrongly claims that an arbitrary animal is a lion. The lack of case marking does not make subject and complement freely reversible.
With true identity, reversal may preserve reference but shift topic:
La ĉefa problemo estas la manko de tempo.
The main problem is the lack of time.
La manko de tempo estas la ĉefa problemo.
The lack of time is the main problem.
The first starts from an already relevant problem and identifies it; the second starts from the lack of time and classifies its importance. Neutral order should make the intended topic clear.
Prepositional and adverbial predicatives
The complement of esti need not be an adjective or noun. A prepositional phrase can give location, ownership, material, origin, affiliation, or condition.
La rezervaj ŝlosiloj estas en la supra tirkesto.
The spare keys are in the top drawer.
Tiu blua jako estas de mia frato.
That blue jacket belongs to my brother.
La tablo estas el reciklita ligno.
The table is made of recycled wood.
These phrases are predicative because esti links them to the subject. Their internal prepositions mark the specific relationship.
Place adverbs work similarly:
La infanoj estas ekstere, sed iliaj manteloj estas ĉi tie.
The children are outside, but their coats are here.
Do not add a preposition before ekstere or ĉi tie unless another relation requires one. The adverb already functions as the location complement.
Infinitive subjects and impersonal descriptions
When a description applies to an action expressed by an infinitive, Esperanto normally uses an -e form:
Promeni ĉiutage estas bone por mia humoro.
Walking every day is good for my mood.
Estas malfacile trovi trankvilan loĝejon en la centro.
It is difficult to find a quiet apartment downtown.
In Promeni estas bone, the subject is the action promeni, so bone describes an action rather than a noun. In the second example, estas malfacile is impersonal and the infinitive provides the relevant activity. English uses adjective good/difficult and often dummy it; Esperanto uses the adverbial ending and needs no dummy pronoun.
Compare a noun subject:
La ĉiutaga promeno estas bona por mia humoro.
The daily walk is good for my mood.
Now bona agrees with the noun promeno. This adjective–adverb contrast follows the category of what is described, not its English translation.
Subjectless environmental clauses
Esti can report a general condition without a subject. The predicative is then adverbial:
En la atendejo estas tro varme.
It is too warm in the waiting room.
Jam estas malfrue; ni daŭrigu morgaŭ.
It is already late; let's continue tomorrow.
Compare La atendejo estas tro varma, which makes the room an explicit subject. The subjectless version frames warmth as an environmental condition. The difference is one of perspective, not truth conditions alone.
An existential clause also uses esti, but its job is to present the existence or presence of an entity: Estas libera seĝo apud la fenestro. That structure has its own information pattern and is covered in Existential Clauses.
Related linking verbs
Other verbs can connect the subject with a predicative description:
| Verb | Relationship | Example |
|---|---|---|
| fariĝi / iĝi | enter a state or role | La ĉielo fariĝis malhela. |
| resti | continue in a state | La pordo restis fermita. |
| ŝajni | appear to have a property | La tasko ŝajnas facila. |
Post la anonco la ĉambro fariĝis silenta.
After the announcement, the room became silent.
La plej grava demando restas sen respondo.
The most important question remains unanswered.
The complements remain predicative and non-accusative. These verbs add change, continuation, or appearance; esti simply links the description to the subject.
Esti is not an English auxiliary template
English uses be + -ing for the progressive. Esperanto normally uses a simple finite verb:
Mi nun legas la raporton.
I am reading the report now.
Mi estas leganta la raporton is grammatically possible but explicitly presents me as being in the ongoing state of reading; it is heavier and much less frequent than English progressive forms. Do not insert esti whenever English has am/is/are.
Likewise, an ordinary copular clause should not be shortened mechanically by replacing esti + adjective with a verbal ending. Esperanto can productively form verbs from many roots—la ĉielo bluas is grammatical—but such a verb may sound more vivid or acquire its own lexical meaning. Neutral prose normally prefers la ĉielo estas blua, while established verbs such as pravi and utili must be learned on their own terms.
Common Mistakes
1. Marking the predicative noun as an object
❌ Mia najbaro estas instruiston.
Incorrect — instruisto identifies the subject; it is not an object.
✅ Mia najbaro estas instruisto.
My neighbor is a teacher.
2. Copying accusative case onto a predicative adjective
❌ La pordoj estas fermitajn.
Incorrect — the plural adjective agrees in number but takes no accusative -n.
✅ La pordoj estas fermitaj.
The doors are closed.
3. Using an adjective for an impersonal condition
❌ Estas malvarma ĉi tie.
Incorrect without a noun subject — the general condition requires an adverbial form.
✅ Estas malvarme ĉi tie.
It is cold here.
4. Inventing an indefinite article before a profession
❌ Ŝi estas unu inĝeniero.
Incorrect for ordinary classification — unu means the number one, not an indefinite article.
✅ Ŝi estas inĝeniero.
She is an engineer.
Key Takeaways
- Esti links a subject with a predicative description or identity; it does not take a direct object.
- Predicative adjectives agree in number but never receive object -n.
- A bare noun normally assigns a category; la + noun can identify a particular known referent.
- Prepositional phrases and place adverbs can function as predicative complements.
- Use -e to describe an infinitive or a subjectless condition: Promeni estas agrable; estas varme.
- Word order remains important when two unmarked noun phrases could otherwise be confused.
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Start learning Esperanto →Related Topics
- Esti: To BeA2 — A complete reference to esti for identity, properties, location, existence, impersonal conditions, participial auxiliaries, and productive derivatives.
- Nouns Used PredicativelyB2 — Use Esperanto nouns after linking verbs and as object complements to express class, identity, role, and result without an inappropriate accusative ending.
- 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.
- Adjectives after EstiB2 — How predicative adjectives after esti describe the subject, agree in number, and remain outside the accusative.
- Predicative Complements and the AccusativeB1 — Distinguish Esperanto predicative complements from accusative objects and attributive modifiers, especially in clauses that describe an object.
- Existential ClausesB2 — Present people, things, and situations with existential estas while keeping existence distinct from location and identification.