Correlatives in Complex Clauses | Esperanto Grammar

Correlatives do more than ask short questions. In a complex sentence, the same ki- forms can introduce an embedded content question, connect a relative clause to an antecedent, or head a clause that functions like a noun phrase. The form is systematic: choose the initial element for the series and the final element for the kind of meaning, then add plural -j or accusative -n only where that ending permits it.

The two dimensions still matter inside a clause

Every correlative combines one of five fixed beginnings with one of nine fixed endings. The beginning identifies the series: ki- asks or relates, ti- points, i- leaves the identity indefinite, ĉi- makes it universal, and neni- makes it negative. The ending identifies the semantic dimension: person or individual (-u), thing (-o), kind (-a), possessor (-es), place (-e), time (-am), reason (-al), manner (-el), or quantity (-om).

These are not freely assembled ordinary roots and suffixes. The forty-five table words belong to a closed, foundational system, presented in full on the table-word system page. Forms such as kiu, kie, and kiom are regular members; a form made by combining two different table endings is not. This matters especially in long sentences, where English may use the same spelling what for a thing, a kind, or an amount. Esperanto requires the correct semantic dimension.

Meaning needed	Choose	Complex-clause example
identity of a person or selectable thing	kiu	Mi demandas, kiu venos.
an unspecified thing or proposition	kio	Mi komprenas, kio okazis.
kind or quality	kia	Montru, kian modelon vi elektis.
place	kie	Mi scias, kie ili loĝas.
quantity	kiom	Diru, kiom ni ŝuldas.

Mi ne scias, kie ŝi lasis la ŝlosilojn.

I don't know where she left the keys.

Ĉu vi memoras, kiom la biletoj kostis?

Do you remember how much the tickets cost?

English speakers often start from an English wh-word and translate it mechanically. Start from the intended dimension instead: what kind of calls for kia, which one for kiu, and how much/many for kiom.

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Build the correlative from meaning in two decisions: first choose the series—question/relative, demonstrative, indefinite, universal, or negative—then choose person, thing, kind, possession, place, time, reason, manner, or quantity.

Embedded questions: a question inside a larger sentence

An embedded content question uses a ki- correlative but is syntactically subordinate. The main clause may report knowing, asking, remembering, checking, or explaining. Unlike English, Esperanto does not switch between question order and statement order: grammatical roles are shown by endings, and the finite verb does not move before the subject.

Mi demandis, kial la kunveno finiĝis tiel frue.

I asked why the meeting ended so early.

Bonvolu kontroli, kiu ankoraŭ ne pagis.

Please check who still hasn't paid.

The correlative has a role inside the embedded clause. Compare kiu, the embedded subject, with kiun, the embedded object:

Mi volas scii, kiu invitis Martin.

I want to know who invited Martin.

Mi volas scii, kiun Martin invitis.

I want to know whom Martin invited.

That final -n is not caused by the verb in the main clause. It comes from the role of kiun in Martin invitis kiun. Similarly, kien marks direction within its own clause, while kie marks location.

Ŝi ne diris, kie ŝi estas, sed ŝi diris, kien ŝi iras.

She didn't say where she is, but she did say where she is going.

Use ĉu for an embedded yes-or-no question, ke for a reported statement, and a ki- correlative for a missing content element. This is a semantic choice, not three interchangeable words for English that or if.

Mi scias, ke Ana venos; mi ne scias, ĉu Leo venos aŭ kiam li decidos.

I know that Ana will come; I don't know whether Leo will come or when he will decide.

Relative correlatives: linking back to an antecedent

In a relative clause, a ki- correlative both links the clause to something outside it and fills a role inside it. With kiu, number normally reflects the antecedent, but case reflects the correlative's role in the relative clause. Those two facts are independent.

Mi salutis la viron, kiu telefonis hieraŭ.

I greeted the man who called yesterday.

Here la viron is the object of salutis, so viron has -n. Inside the relative clause, however, kiu is the subject of telefonis, so it has no -n.

La viro, kiun mi vidis hieraŭ, telefonis hodiaŭ.

The man whom I saw yesterday called today.

Now la viro is the subject of the main clause, while kiun is the object of vidis inside the relative clause. English can omit object whom/that in “the man I saw.” Standard Esperanto cannot simply omit kiun: the relative element is the explicit link and clause member.

La kolegoj, kiujn vi renkontis ĉe la kongreso, laboras en tri landoj.

The colleagues whom you met at the congress work in three countries.

The plural -j is licensed on -u correlatives, and precedes accusative -n: kiujn. The -a series can also take both endings when it modifies an expressed or understood noun: kiaj, kiajn. The -o series takes -n but normally not -j; rare forms such as tioj occur only when a writer deliberately treats separate “things” as countable nouns. The remaining endings do not pluralize.

Possessive kies never takes -j or -n. Case belongs to the possessed noun phrase, not to kies itself.

Ni dungis la kandidatinon, kies sperto plej bone kongruas kun la posteno.

We hired the candidate whose experience best matches the position.

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For a relative correlative, ignore the antecedent's case when choosing -n. Reconstruct only the relative clause: mi vidis kiun requires kiun; kiu telefonis requires kiu.

Place, time, manner, and the TI–KI pattern

Relative clauses are not limited to kiu, kio, and kies. Kie, kiam, kiel, and other ki- correlatives can relate the subordinate clause to a place, time, or manner. A matching ti- correlative in the main clause makes the relationship explicit.

Ni renkontiĝu tie, kie la pado atingas la riveron.

Let's meet where the path reaches the river.

Mi telefonos tiam, kiam mi scios la finan rezulton.

I'll call when I know the final result.

Faru ĝin tiel, kiel ni interkonsentis.

Do it the way we agreed.

The full ti–ki pairing is transparent and neutral in all registers. In many contexts, the ti- half may be omitted when its role is obvious: Ni renkontiĝu, kie la pado atingas la riveron and Mi telefonos, kiam mi scios are normal. Keeping it can add clarity, balance, or emphasis. This is accepted variation, not a difference in grammaticality.

Do not, however, imitate English by stranding a preposition. Esperanto normally places the preposition with the correlative: la ilo, per kiu mi malfermis ĝin, not a structure modeled on “the tool which I opened it with.”

Jen la programo, per kiu ni redaktas la filmetojn.

Here is the program with which we edit the videos.

Free relatives and reference to a whole proposition

A relative clause can itself function as a noun phrase, without an overt noun antecedent. In Kiu alvenos unue, tiu ricevos la ŝlosilon, the first clause means “whoever arrives first.” In neutral prose, the paired tiu makes the structure especially clear.

Kiu bezonas helpon, tiu diru tion nun.

Whoever needs help should say so now.

Mi faris tion, kion vi petis, kaj nenion pli.

I did what you asked, and nothing more.

In the second example, tion can be omitted—Mi faris, kion vi petis—because the kio clause itself fills the object slot. This omission is well established in actual usage. For learners, retaining the matching ti- form is often the clearest first choice when the structure could otherwise be misread.

Relative kio can also refer not to a single noun but to the content of an entire preceding clause. This is why kio, rather than kiu, appears after a complete proposition.

La trajno denove malfruis, kio surprizis neniun.

The train was late again, which surprised no one.

Negative correlatives preserve their ordinary scope inside complex clauses. Mi aŭdis, ke neniu venis negates the participants in the reported event; it does not mean that the hearing itself failed to happen.

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The foundational table supplies the forms; clause syntax supplies their role. Corpus usage supports ordinary omission of a recoverable ti- counterpart, but it does not license invented correlatives or English-style omission of the relative linker.

Common Mistakes

Translating English “what” without choosing a dimension

❌ Mi ne scias, kiu okazis.

Incorrect — kiu asks which person or selectable individual, not what event occurred.

✅ Mi ne scias, kio okazis.

I don't know what happened.

Copying the antecedent's case onto the relative word

❌ Mi vidis la viron, kiun telefonis hieraŭ.

Incorrect — the relative word is the subject of telefonis, despite viron being a main-clause object.

✅ Mi vidis la viron, kiu telefonis hieraŭ.

I saw the man who called yesterday.

Omitting an object relative as English does

❌ La libro, mi aĉetis hieraŭ, jam malaperis.

Incorrect — standard Esperanto requires a relative linker that also marks the missing object.

✅ La libro, kiun mi aĉetis hieraŭ, jam malaperis.

The book that I bought yesterday has already disappeared.

Pluralizing an ineligible correlative

❌ Mi ne memoras, kiesj estas tiuj jakoj.

Incorrect — the -es series never takes plural -j.

✅ Mi ne memoras, kies estas tiuj jakoj.

I don't remember whose those jackets are.

Inventing a hybrid instead of selecting a table word

❌ Mi havas neniuom da libera tempo hodiaŭ.

Incorrect — neniuom wrongly combines the complete form neniu with the -om ending.

✅ Mi havas neniom da libera tempo hodiaŭ.

I have no free time today.

Key Takeaways

In complex clauses, ki- correlatives introduce embedded content questions, relative clauses, and free relatives.
Choose both dimensions: the series beginning and the semantic ending.
On relative kiu, number follows the antecedent, but case comes from the role inside the relative clause.
Esperanto keeps an explicit relative linker where English can omit that or whom.
Matching pairs such as tie–kie and tiel–kiel make clause relations explicit; the ti- half is often omissible when clearly recoverable.

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