Cause and result are two views of the same relation, but Esperanto marks them differently. Ĉar introduces a clause that gives a cause; pro introduces a noun phrase naming a cause; tial points to a reason already identified; and do or sekve presents a conclusion or consequence. Choosing the right marker tells the listener not just that two facts are connected, but how to reason from one to the other.
Ĉar introduces the cause
Ĉar is a clause introducer. It must be followed by a clause with its own verb, and that clause answers kial? “why?” It can follow or precede the main clause.
Mi nuligis la vojaĝon, ĉar mi havis febron.
I canceled the trip because I had a fever.
Ĉar la lasta buso jam foriris, ni piediris hejmen.
Because the last bus had already left, we walked home.
The order changes information flow. With the cause second, the speaker first makes a claim and then justifies it. With the cause first, the speaker establishes the circumstances before presenting the result. The logical relation is the same.
In conversation (informal), a ĉar clause can stand as a short answer because the main clause is recoverable.
—Kial vi ne venos morgaŭ? —Ĉar mi devas labori.
—Why aren't you coming tomorrow? —Because I have to work.
English also allows a free-standing because answer, so the structure is familiar. The important difference is that Esperanto ĉar cannot directly introduce a bare noun.
Pro introduces a cause as a noun phrase
Use pro + noun phrase when the cause is presented as a thing, event, or circumstance rather than as a full clause.
La matĉo estis nuligita pro la pluvo.
The match was cancelled because of the rain.
Pro teknika problemo la retejo ne funkcias.
Because of a technical problem, the website is not working.
To put a clause after pro, use pro tio, ke.... The demonstrative tio is the complement of the preposition, and the ke clause explains what tio refers to.
Ni malfruis pro tio, ke la trajno haltis inter du stacioj.
We were late because the train stopped between two stations.
At A2, ĉar + clause is usually shorter and easier. Pro tio, ke is useful when the causal phrase must occupy a noun-like position or when the writer wants an explicit parallel with pro + noun. For purpose rather than cause, use por; see por or pro.
Tial points to a reason
Tial literally means “for that reason.” It is an -al table word, not a conjunction. It can refer back to an entire preceding statement or forward to a ke clause.
La vojo estas fermita. Tial ni devas iri tra la centro.
The road is closed. For that reason, we have to go through the center.
Mi elektis tiun kurson tial, ke ĝi okazas vespere.
I chose that course for the reason that it takes place in the evening.
Compare the direction of packaging:
Ni iris tra la centro, ĉar la vojo estis fermita.
We went through the center because the road was closed.
La vojo estis fermita; tial ni iris tra la centro.
The road was closed; therefore, we went through the center.
The first sentence places the reason in a subordinate clause. The second makes the cause a previous statement and uses tial inside the consequence. English because and therefore make the same broad contrast, but English speakers sometimes copy the familiar word order while retaining the wrong Esperanto marker.
Standard usage can combine ĉar and tial for extra clarity: Ĉar la vojo estis fermita, tial ni iris tra la centro. This is grammatically accepted, not a forbidden “double connector.” In concise prose, however, either ĉar or tial normally makes the relation clear by itself.
Do: a conclusion drawn in context
Do presents what follows as a conclusion or consequence of previous information. It is often lighter and more interactional than sekve. Depending on context, English translates it as “so,” “then,” or “therefore.”
La vendejo jam estas fermita, do ni revenu morgaŭ.
The shop is already closed, so let's come back tomorrow.
Vi jam finis la raporton? Do ni povas sendi ĝin hodiaŭ.
You've already finished the report? Then we can send it today.
The second example is an inference and a speech act: the speaker accepts new information and turns it into a practical proposal. Do also appears emphatically in questions and directives, where the logical conclusion may be weak and the interactional force stronger.
Kion do vi proponas?
So what do you propose, then?
Nu, diru do, kio okazis.
Well, tell me then what happened. (informal)
That directive can sound impatient or encouraging depending on voice and context. Do is not a politeness word. If the request is sensitive, change the request form rather than piling on bonvolu:
Ĉu vi povus klarigi la lastan paŝon? Mi ne vidas, kiel la konkludo sekvas.
Could you explain the last step? I don't see how the conclusion follows.
Sekve: an explicit consequence
Sekve marks a consequence or conclusion particularly clearly. It is common in reasoned exposition (formal/academic) and also possible in careful everyday speech. Because it claims that the next point follows from the earlier one, it is stronger than mere chronological poste “afterwards.”
La kandidato ne sendis la postulatajn dokumentojn; sekve, ni ne povis pritaksi la peton.
The candidate did not send the required documents; consequently, we could not assess the application. (formal)
La du mezuroj donis la saman rezulton. Sekve, la eraro verŝajne ne troviĝas en la instrumento.
The two measurements gave the same result. Consequently, the error probably is not in the instrument. (academic)
The second sentence separates two dimensions: sekve gives the reasoning relation, while verŝajne states confidence. A conclusion can follow reasonably without being certain.
Result is not the same as inference strength
Markers such as tial, do, and sekve connect propositions. Eble, verŝajne, ŝajne, and inferential devas express how strongly the speaker endorses a conclusion.
| Form | Core contribution | Typical force |
|---|---|---|
| eble | one possibility | weak commitment |
| verŝajne | probable conclusion | more likely than not |
| ŝajne | judgment from appearances | appearance may differ from reality |
| devas | strong inference from evidence | speaker treats the conclusion as necessary |
La fenestro estas malfermita, do eble iu jam venis.
The window is open, so maybe someone has already arrived.
La lumoj estas estingitaj kaj neniu respondas; ili devas jam dormi.
The lights are off and nobody answers; they must already be asleep.
The first conclusion is tentative. The second presents a strong inference, not an obligation to sleep. Context distinguishes inferential devas from ordinary necessity.
Norm, variation, and discourse style
The distinction between clause-introducing ĉar and reason-referring tial is part of standard grammar and is documented from foundational usage onward. Do as conclusion and as emphatic conversational particle is also established. Combining ĉar... tial is accepted variation, though often heavier than necessary. Sekve is a transparent adverb and especially frequent in explicit reasoning. The frequency and punctuation of these markers are stylistic choices; their logical relations are not.
Common Mistakes
Putting a noun directly after ĉar
❌ La flugo malfruis ĉar la nebulo.
Incorrect — ĉar must introduce a clause, not a bare noun phrase.
✅ La flugo malfruis pro la nebulo.
The flight was delayed because of the fog.
Using pro ke without a nominal anchor
❌ Ni foriris pro ke estis malfrue.
Incorrect — pro cannot directly govern a ke clause.
✅ Ni foriris, ĉar estis malfrue.
We left because it was late.
Reversing cause and result
❌ Tial la vojo estis fermita, ni elektis alian itineron.
Incorrect structure for the intended meaning — tial belongs to the consequence, not to a clause that merely states the cause.
✅ La vojo estis fermita; tial ni elektis alian itineron.
The road was closed; therefore, we chose another route.
Choosing a concession marker for an expected result
❌ La vojo estis glita; tamen ni veturis malrapide.
Wrong logical marker for the intended relation — driving slowly is presented as the expected result.
✅ La vojo estis glita; tial ni veturis malrapide.
The road was slippery; therefore, we drove slowly.
Translating every conversational “so” as do
❌ Do, hieraŭ mi renkontis mian kolegon ĉe la stacidomo.
Unmotivated do if this simply opens a story and no conclusion is being drawn.
✅ Nu, hieraŭ mi renkontis mian kolegon ĉe la stacidomo.
Well, yesterday I met my colleague at the station.
Key Takeaways
Use ĉar + clause or pro + noun phrase to express a cause. Use tial for “for that reason,” do for a contextual conclusion, and sekve for an explicit consequence. Then choose eble, verŝajne, ŝajne, or inferential devas separately to show how strongly you accept the conclusion.
Related Topics
- Cause ClausesA2 — Explain reasons and motives with finite ĉar clauses while distinguishing them from pro phrases, tial, and coordinating links.
- Do: ConsequenceB2 — Use do for conclusions, consequences, and discourse emphasis while distinguishing it from tial, sekve, conjunctions, and English ‘so.’
- Tial: The Demonstrative Reason CorrelativeB1 — Use tial to point to an established reason, and distinguish it from ĉar, do, and expressions of purpose.
- Ĉar or Tial?B1 — Use ĉar to introduce a cause clause and tial to point to that cause while presenting its result.
- Por or Pro?B1 — Choose por for intended goals, beneficiaries, and exchange, and pro for causes, motives, and reasons already producing an effect.