Coordination joins two or more expressions that perform the same syntactic job. Kaj adds, aŭ offers alternatives, sed contrasts, and paired forms such as nek... nek make the relation explicit on every member. The central discipline is parallelism: coordinate whole subjects with subjects, objects with objects, and modifiers with modifiers, while marking each member for the role it actually has.
Coordinate expressions with the same role
The coordinated members can be single words or much larger phrases. What matters is their function in the containing clause.
Marta kaj ŝia pli juna frato alvenos vendrede vespere.
Marta and her younger brother will arrive on Friday evening.
Ni bezonas pli grandan tablon kaj du pliajn seĝojn.
We need a larger table and two more chairs.
La kunveno estos aŭ en la biblioteko aŭ en la komunuma centro.
The meeting will be either in the library or in the community center.
In the first sentence, two noun phrases form the subject. In the second, two noun phrases form a coordinated object. In the third, two prepositional phrases are alternative place complements. The second member does not become an afterthought merely because it follows a conjunction; it has the same role as the first.
This gives a useful diagnostic. Remove each member in turn. Both remaining sentences should have the intended structure:
- Marta alvenos / ŝia pli juna frato alvenos
- Ni bezonas pli grandan tablon / Ni bezonas du pliajn seĝojn
- La kunveno estos en la biblioteko / La kunveno estos en la komunuma centro
When that test fails, the apparent coordination may join unlike constituents or attach at the wrong level.
Case belongs to every coordinated noun phrase
Esperanto case marking makes coordination robust under reordering, but each nominal member must show its own role. Coordinated direct objects each take -n.
Mi aĉetis panon, fromaĝon kaj maturajn tomatojn por la pikniko.
I bought bread, cheese, and ripe tomatoes for the picnic.
— Ĉu vi invitis Aminan aŭ ŝian kolegon al la intervjuo? — Aminan; ŝia kolego ne povos veni.
— Did you invite Amina or her colleague to the interview? — Amina; her colleague will not be able to come.
Panon, fromaĝon, tomatojn, Aminan, and kolegon are all objects. A conjunction cannot carry case for its neighbor, and the -n on the first item does not extend invisibly over the second.
The entire coordinated object may be fronted for contrast because its case makes the role clear:
Panon kaj fromaĝon ni jam havas; fruktojn ni ankoraŭ devas aĉeti.
Bread and cheese we already have; fruit we still need to buy.
That is accepted marked order, not the neutral default. In an out-of-context report, Ni jam havas panon kaj fromaĝon is easier. Moving only part of a close coordinate unit can produce forced contrasts or momentary ambiguity, so move the unit together unless a split is deliberately contrastive.
Sharing or repeating a preposition
One preposition can govern multiple coordinated complements when they have the same relation:
Ni tranĉis la branĉojn per segilo kaj tondilo.
We cut the branches with a saw and shears.
This is equivalent in core meaning to per segilo kaj per tondilo. Repeating the preposition is useful when the members are long, when each deserves separate emphasis, or when the boundary could be misunderstood.
La raporto estis verkita por la loka konsilio kaj por la asocioj, kiuj administras la rifuĝejojn.
The report was written for the local council and for the associations that manage the shelters.
Here repetition makes the two beneficiaries immediately visible before the long relative clause. It also prevents la asocioj from being misread as coordinated directly with some noun inside the first phrase.
Do not share a preposition across members with different roles. Say de la stacidomo ĝis la hotelo, not as though de governed both endpoints. Esperanto even permits coordinated prepositions before one complement—por kaj per Esperanto—but this compressed pattern is best reserved for short, clearly parallel relations. In dense prose, repeat the complement: por Esperanto kaj per Esperanto.
Kaj, aŭ, sed, and paired coordinators
Kaj presents all members as added; aŭ presents alternatives. Unmarked aŭ can be exclusive or inclusive according to context, just as English “or” can.
Vi povas sendi la dokumenton retpoŝte aŭ alŝuti ĝin per la formularo.
You can send the document by email or upload it using the form.
If both options are allowed, say so when that matters: Vi povas elekti unu metodon aŭ ambaŭ. The written form kaj/aŭ occurs especially in (formal) administrative prose, but an explicit wording is clearer and easier to read.
Sed coordinates contrasted members of the same role, often after negation:
La trajno foriros ne je la oka, sed je la oka kaj duono.
The train will leave not at eight but at eight thirty.
Mi bezonas ne konsilon, sed praktikan helpon.
I need not advice but practical help.
The second example preserves object marking on both konsilon and helpon. The contrast changes the choice of member, not its grammatical role.
Paired coordinators mark the scope at both edges:
Kaj la instruistoj kaj la lernantoj petis pli trankvilan laborejon.
Both the teachers and the students requested a quieter workspace.
Ni ricevis nek klaran respondon nek novan limdaton.
We received neither a clear answer nor a new deadline.
Aŭ vi telefonu al ŝi hodiaŭ, aŭ vi atendu ĝis lundo.
Either call her today, or wait until Monday.
Paired kaj... kaj, aŭ... aŭ, and nek... nek are neutral standard Esperanto. Repeating the coordinator adds explicitness and often emphasis; it is not required for a simple two-item list.
Lists and punctuation
In a list of three or more members, ordinary Esperanto usually places the conjunction only before the last member and separates earlier members with commas.
Por la ekskurso kunportu akvon, sunĉapelon, komfortajn ŝuojn kaj malpezan jakon.
For the excursion, bring water, a sun hat, comfortable shoes, and a light jacket.
A comma is not normally required before the final kaj merely because English style uses an Oxford comma. Add punctuation when it reflects an actual pause, parenthesis, or needed boundary—not by mechanical transfer from an English house style.
Repeated kaj can be rhetorical:
Post la vojaĝo ni estis kaj lacaj kaj malsataj kaj tute malsekaj.
After the trip we were tired, hungry, and completely soaked.
This emphatic piling-up is natural in conversation and narrative. A plain list—lacaj, malsataj kaj tute malsekaj—is stylistically more neutral.
Agreement and coordinated subjects
Two singular noun phrases joined by kaj normally denote a plural subject. Esperanto verbs do not agree in number, but a predicative adjective does.
La kuirejo kaj la banĉambro estas pretaj, sed la dormoĉambro ankoraŭ ne.
The kitchen and the bathroom are ready, but the bedroom is not yet.
With aŭ, number depends on the intended reference and can become awkward when the alternatives differ in number. Because the verb never reveals the difference, rewrite a predicate adjective if its agreement would force an uncertain interpretation. Aŭ la direktoro aŭ la vicdirektoroj ĉeestos la kunvenon avoids the problem better than attaching one adjective to that mixed-number subject.
Determiners and modifiers also affect grouping. La direktoro kaj la kasisto clearly names two roles or people. La direktoro kaj kasisto can invite the reading that one person is both director and cashier. Repeat la when two referents are intended.
Scope and constituent boundaries
Coordination often creates genuine scope ambiguity. Consider malnovaj libroj kaj revuoj. It may mean old books plus unspecified magazines, or old books and old magazines. Grammar alone does not settle the reach of malnovaj.
Ni fordonos malnovajn librojn kaj malnovajn revuojn.
We will give away old books and old magazines.
Ni fordonos la malnovajn librojn kaj kelkajn revuojn.
We will give away the old books and some magazines.
Repeat the modifier or choose a distinct determiner when scope matters. “Free” word order is not a cure: pulling malnovajn away from its head makes the structure harder, not more expressive.
Shared material can also be structurally unclear. Ŝi renkontis la amikon de Marta kaj Petro may mean one friend shared by Marta and Petro, while Ŝi renkontis la amikon de Marta kaj la amikon de Petro unmistakably names two friend-relations. The coordination and shared dependents page develops such ellipsis in depth.
Common Mistakes
Omitting case on the second object
❌ Mi invitis Martan kaj ŝia frato.
Incorrect — both coordinated people are direct objects.
✅ Mi invitis Martan kaj ŝian fraton.
I invited Marta and her brother.
Coordinating unlike roles
❌ Ni parolis pri la buĝeto kaj la direktoron.
Incorrect — pri la buĝeto and la direktoron do not have the same role.
✅ Ni diskutis la buĝeton kaj demandis la direktoron.
We discussed the budget and asked the director.
Leaving modifier scope unresolved
❌ Ili vendas uzitajn telefonojn kaj komputilojn.
Ambiguous — it is unclear whether the computers are also used.
✅ Ili vendas uzitajn telefonojn kaj uzitajn komputilojn.
They sell used phones and used computers.
Treating a fronted coordinate as neutral
❌ Teon kaj kafon la gastoj mendis.
Poor as a context-free report — the fronted objects sound contrastive.
✅ La gastoj mendis teon kaj kafon.
The guests ordered tea and coffee.
Key Takeaways
- Coordinate members that perform the same syntactic role.
- Mark every nominal member for its own case; kaj and aŭ do not replace -n.
- A shared preposition is standard when both complements have the same clear relation; repeat it for clarity or contrast.
- Repetition resolves modifier, determiner, and dependency scope.
- Coordinated units can be reordered, but neutral SVO and intact constituent boundaries remain the safest defaults.
Related Topics
- Kaj: Addition and CoordinationA2 — Coordinate parallel words, phrases, and clauses with kaj while preserving their grammatical roles, tense, mood, and scope.
- Aŭ: AlternativesA2 — Coordinate alternative words, phrases, and clauses with aŭ while controlling exclusivity, scope, ellipsis, and punctuation.
- Nek… Nek…B2 — How repeated nek coordinates two or more equally negated words, phrases, or clauses without an additional ne.
- Coordinated ObjectsB1 — How objects joined by kaj, aŭ, nek, or paired conjunctions share a role while retaining the right case and agreement.
- Coordination and Shared DependentsB2 — Share subjects, objects, verbs, prepositions, and clause frames across coordinated structures without creating scope or attachment ambiguity.
- Avoiding Ambiguity in Free OrderB1 — Use Esperanto's flexible constituent order without obscuring grammatical roles, modifier attachment, particle scope, or information structure.