Catalan relative on means “where,” “in which,” or, in suitable directional contexts, “to which”: la casa on vivim, el museu on anem. It is an invariable locative relative, so it does not agree with casa, museu, pobles, or ciutats.
Its core domain is literal location. Catalan uses on less freely than English “where” or Spanish donde for times, situations, degrees, and abstract frameworks; those contexts usually require en què or an agreeing form of el qual.
Building a relative with on
Begin with a complete locative clause and replace its place phrase:
Treballem en aquest edifici. → Aquest és l'edifici on treballem.
We work in this building. → This is the building where we work.
Vam conèixer l'Aina en aquella plaça. → Aquella és la plaça on vam conèixer l'Aina.
We met Aina in that square. → That is the square where we met Aina.
In each result, on fills the place slot. It is not the subject or direct object of the relative clause: the omitted subject of treballem is nosaltres, while l'Aina is the direct object of vam conèixer.
On alone and optional a on
For both static location and direction, on can stand alone. It can also be preceded by a, though the version without a is more frequent in the general standard.
Aquesta és l'escola (a) on treballa la meva germana.
This is the school where my sister works.
El refugi (a) on ens encaminàvem era encara a dues hores de camí.
The shelter we were heading toward was still a two-hour walk away.
The parentheses show a genuine standard alternation, not uncertainty: on and a on are both possible here. Adding a can make direction more explicit, but it is not required.
When a nominal antecedent is present, locative on alternates with a prepositional relative:
| Relation | With on | Alternative |
|---|---|---|
| static location | la sala on ens reunim | la sala en què / en la qual ens reunim |
| destination | el museu (a) on anem | el museu al qual anem |
| source | la platja d'on surt la barca | la platja de la qual surt la barca |
| path | el pont per on passem | el pont pel qual passem |
With simple què, locative alternation is limited to static en què. For a directional goal, use (a) on or al qual, not a mechanical a què.
Prepositions that add spatial meaning
The preposition before on tells the reader how the event relates to the place. A source needs de or des de; a route needs per; limits and direction can use fins (a) and cap (a).
La platja des d'on ha sortit la barca és just davant de casa.
The beach the boat left from is right in front of the house.
La drecera per on hem de passar està ben senyalitzada.
The shortcut we have to take is well marked.
Des d'aquí fins (a) on comença el bosc hi ha uns tres quilòmetres.
From here to where the forest begins, it's about three kilometers.
English can strand “from” or “through” at the end: “the beach the boat left from.” Catalan places it before on: d'on / des d'on, never on ... de in standard syntax.
The same forms occur without an explicit noun antecedent: Anirem on ens diguis “We'll go wherever you tell us,” Vinc d'on vens tu “I come from where you come from.” With demonstrative adverbs, Catalan can say allà on and allí on.
Literal, institutional, and metaphorical places
Physical places are the clearest antecedents: casa, carrer, escola, illa, habitació. An institution can license on when it is conceptualized as a workplace or physical setting: l'empresa on treballo, l'hospital on el van operar. This is a location reading, not agreement with the noun's meaning.
Catalan is more restrictive with metaphorical location. For circumstances, illnesses, systems, levels, and abstract states, edited usage favors en què / en el qual rather than on:
Ens trobem en una situació en què qualsevol retard pot tenir conseqüències greus.
We are in a situation in which any delay can have serious consequences.
És una malaltia en la qual el pacient necessita controls freqüents.
It is an illness in which the patient needs frequent checkups.
Temporal antecedents behave similarly. Say els anys en què vivíem a Reus or el dia que vam arribar, not normally els anys on or el dia on in careful Catalan. For a scale or degree, use the preposition selected by the expression: l'altura a la qual pot arribar, not l'altura on pot arribar.
On versus que: location or direct object?
A place noun does not automatically require on. Its grammatical function inside the relative decides the form.
El poble que vam visitar dissabte és a prop de la frontera.
The village that we visited on Saturday is near the border.
El poble on vam passar la nit és a prop de la frontera.
The village where we spent the night is near the border.
In the first sentence, visitar takes el poble as a direct object, so the relative is que. In the second, al poble is the setting of passar la nit, so locative on is appropriate. Translating both by English “where” would conceal this structural difference.
The same principle prevents an automatic Spanish-style personal a. A person uses subject/direct-object que in ordinary contexts—la guia que vam veure—or a genuinely governed prepositional relative—la guia amb qui vam parlar. On is never a substitute for a human object.
On already fills the location slot
Because on itself represents the locative phrase, do not normally add resumptive hi for that same place in formal usage:
Aquesta és la casa on viu la Júlia.
This is the house where Júlia lives.
Aquesta és la casa on hi viu la Júlia is a common (informal) resumptive pattern, but edited prose normally chooses on viu or en què viu. Similarly, source d'on replaces a de-phrase directly: el poble d'on vinc, not el poble d'on en vinc when both forms refer to the same source.
For independent clauses in which hi itself resumes a location, see the locative pronoun hi.
There are legitimate sentences in which another clitic has a different function. La ciutat on hi ha tres universitats is standard because hi belongs to lexicalized existential haver-hi. In Aquest és el poble on me'l van lliurar, on gives the location, me the recipient, and l' a previously mentioned masculine direct object. The cluster keeps its ordinary order and elision; on el me van lliurar does not become possible merely because a relative precedes it.
On with a nonfinite predicate
The locative dependency can belong to an infinitive inside the relative clause:
Necessitem una sala on poder treballar sense interrupcions.
We need a room where we can work without interruptions.
Ja han confirmat l'aula on ens hem de reunir demà.
They have confirmed the classroom where we have to meet tomorrow.
In the second example, on supplies the place of pronominal reunir-nos, while ens belongs to the verb itself. It would be wrong to add hi for the same classroom. Relative on stays at the front of its clause; it never attaches to the infinitive with a hyphen.
A dialogue with an unambiguous antecedent
—Recordes el cafè on vam conèixer l'Èric? —Sí; també recordo la plaça per on vam tornar a casa aquella nit.
Do you remember the café where we met Èric? —Yes; I also remember the square we crossed on our way home that night.
El cafè is the static setting selected by bare on. La plaça is interpreted as part of the route, so per on makes the path relation explicit.
Regional and register perspective
Locative on, optional (a) on, and spatial combinations such as d'on and per on belong to both IEC and AVL standards. The relative without a is more frequent generally, though regional and individual preferences vary across Central, Valencian, Balearic, Northwestern, Northern, and Alguerese usage. The strongest register contrast concerns resumptive forms: (informal) la casa que hi visc or la casa on hi visc occurs widely, whereas (formal) prose uses la casa on visc / en què visc.
Common Mistakes
1. Using on for a nonlocative relation.
❌ No entenc la raó on han rebutjat la proposta.
Incorrect—the relation is causal, not locative.
✅ No entenc la raó per què han rebutjat la proposta.
I don't understand the reason why they rejected the proposal.
2. Using bare que without representing the location.
❌ Aquest és el pis que viu l'Arnau.
Incorrect—the relative clause needs a locative relative, not bare subject/direct-object que.
✅ Aquest és el pis on viu l'Arnau.
This is the apartment where Arnau lives.
3. Stranding a path preposition.
❌ La drecera que hem de passar per està tallada.
Incorrect—the path preposition cannot be stranded at the end of the relative clause.
✅ La drecera per on hem de passar està tallada.
The shortcut we have to take is closed.
4. Choosing on merely because the antecedent names a place.
❌ El museu on vam visitar dissabte tanca els dilluns.
Incorrect—visitar selects the museum as its direct object, not as a location.
✅ El museu que vam visitar dissabte tanca els dilluns.
The museum we visited on Saturday is closed on Mondays.
5. Combining on with another locative relative form.
❌ La sala en on farem la reunió té poca llum.
Incorrect—do not combine en and on in this way.
✅ La sala on farem la reunió / en què farem la reunió té poca llum.
The room where we'll hold the meeting has little light.
Key Takeaways
Use invariant on for literal location or direction, optionally preceded by a. Add spatial prepositions when they contribute source, route, limit, or direction: d'on, des d'on, per on, fins (a) on. Prefer en què or a form of el qual for times and abstract frameworks, distinguish a locative antecedent from a place noun functioning as a direct object, and avoid redundant hi when on already fills the location slot.
Related Topics
- Relative QueB1 — Use invariant unstressed que to build Catalan subject and direct-object relative clauses without omission, agreement, or stranded prepositions.
- Prepositional Relatives with Què, Qui, and El QualB1 — Choose què, qui, or the agreeing forms of el qual after Catalan prepositions and avoid stranded or resumptive alternatives.
- Hi for LocationsB1 — Use hi for static places, destinations, and paths, and keep obligatory hi in the existential verb haver-hi.
- Locative EnB1 — Use locative en for places of origin introduced by de, and distinguish this productive source use from lexicalized pronominal verbs.
- Prepositions and Locutions of PlaceA2 — Locate people and things with davant de, darrere de, al costat de, prop de, lluny de, dins de, fora de, and orientation phrases.
- Relative ClausesB2 — Distinguish restrictive and nonrestrictive Catalan relative clauses and choose que, què, qui, on, or el qual with accurate punctuation and register.