The four spellings encode four different structures. Perquè is normally a conjunction introducing a cause or a purpose; per què is the preposition per followed by interrogative or relative què; el perquè is a noun meaning “the reason”; and per a què asks about an intended purpose, roughly “what for?” English often writes because, why, the reason why, and what for, but translation alone is unreliable because English why can ask either for a cause or for a purpose.
The decisive questions are syntactic and semantic: Does a clause explain a cause? Does it name a goal? Is què being questioned? Can the whole expression be pluralized? Does per belong to a relative construction? Once those questions are answered, spacing, accent, and mood follow predictably.
Quick-reference table
| Meaning and structure | Form | Diagnostic | Typical continuation |
|---|---|---|---|
| cause: “because” | perquè | answers per què? with an asserted explanation | usually indicative |
| purpose: “so that” | perquè | names the intended result of the main action | subjunctive |
| direct or embedded “why” | per què | què carries interrogative force | question word order or an embedded clause |
| relative “for which/by which” | per què | has an antecedent and can often become pel qual | relative clause |
| the noun “reason” | el perquè | takes a determiner and can pluralize: els perquès | noun syntax |
| purpose question: “what for?” | per a què | asks what use or goal something has | often servir, voler, necessitar |
Perquè: cause versus purpose
One-word perquè links clauses. With a cause, it gives the grounds for an assertion, and the ordinary mood is indicative because the speaker presents that cause as real. With a purpose, it presents a desired outcome that has not yet been established, so the subordinate verb is subjunctive.
Minimal pair 1: cause or intended result
He tancat la porta del balcó perquè entrava fum del restaurant.
I closed the balcony door because smoke was coming in from the restaurant. (asserted cause)
He tancat la porta del balcó perquè no entri fum del restaurant.
I closed the balcony door so that smoke won't come in from the restaurant. (intended result)
The main event is identical. The imperfect entrava explains what was already happening; the present subjunctive entri names the result the closing is meant to produce. This cause–purpose distinction is developed further in purpose connectors.
Minimal pair 2: asserted and rejected causes
No ha vingut perquè està malalta.
She hasn't come because she is ill. (the illness is asserted as the cause)
No ha vingut perquè estigui malalta, sinó perquè havia de cuidar el seu fill.
She hasn't stayed away because she is ill, but because she had to look after her son. (the first cause is rejected)
The subjunctive in the second sentence does not make the illness “uncertain” in a vague sense. It places that explanation outside the speaker's assertion: the speaker explicitly rejects it. This is a marked use, not a reason to put every negative causal clause in the subjunctive.
Per què: asking for a cause
In per què, the words remain separate because què is an interrogative pronoun governed by per. It appears in direct questions and embedded questions. The accent on què is obligatory.
Minimal pair 3: question and answer
Per què has canviat la data de la reunió?
Why did you change the date of the meeting?
He canviat la data perquè dijous la sala no està disponible.
I changed the date because the room isn't available on Thursday.
An embedded question keeps the two-word form even without question marks:
Encara no entenc per què han descartat la proposta més barata.
I still don't understand why they rejected the cheapest proposal.
Here per què han descartat... is the information not understood. It is not a causal clause explaining entenc, so writing one-word perquè would misidentify its syntax. See embedded questions for their word order.
Per què as a relative sequence
The same spelling can occur when per is required by the relation and què is a relative pronoun with an antecedent. This use is more common in careful prose than in spontaneous conversation. A useful test is replacement by an inflected relative such as pel qual, per la qual, pels quals, or per les quals.
Minimal pair 4: interrogative or relative
No sabem per què van suspendre l'acte.
We don't know why they cancelled the event. (embedded question; no antecedent)
No sabem els motius per què van suspendre l'acte.
We don't know the reasons for which they cancelled the event. (relative; motius is the antecedent)
In formal writing, els motius pels quals van suspendre l'acte is often clearer. Do not assume that every sequence following motiu must be one-word perquè: the governing preposition and the relative antecedent determine the structure.
El perquè: a countable noun
El perquè means “the reason” or “the explanation.” Because it is a masculine noun, it can take determiners, adjectives, and the plural els perquès. This noun test is decisive: a conjunction cannot be pluralized.
Minimal pair 5: an embedded question or a noun phrase
La comissió vol saber per què s'ha endarrerit l'obra.
The committee wants to know why the construction work has been delayed. (question clause)
La comissió vol saber el perquè de l'endarreriment de l'obra.
The committee wants to know the reason for the delay in the construction work. (noun phrase)
The noun construction is somewhat denser and is common in explanatory, administrative, and journalistic prose (formal). In everyday speech, a clause with per què is often lighter. The plural is fully possible when several explanations are at issue:
L'informe analitza els perquès del descens de participació.
The report analyzes the reasons for the decline in participation. (formal)
Per a què: asking about purpose or use
Use per a què when the question is “for what purpose?” or “what use does this have?” The answer normally names a goal rather than a prior cause.
Minimal pair 6: cause or purpose
Per què han instal·lat una rampa a l'entrada?
Why have they installed a ramp at the entrance? (asks for the motivating cause)
Per a què han instal·lat una rampa a l'entrada?
What have they installed a ramp at the entrance for? (asks its intended function)
The first might be answered Perquè la inspecció ho exigia (“because the inspection required it”). The second invites Perquè les persones amb mobilitat reduïda hi puguin accedir (“so that people with reduced mobility can enter”). The physical situation is unchanged; only the requested relation differs.
Minimal pair 7: reason for choosing or intended use
Per què vols aquesta clau petita?
Why do you want this small key? (what motivates your wish?)
Per a què vols aquesta clau petita?
What do you want this small key for? (what will you use it for?)
In much spontaneous Central and Balearic speech, and in other areas depending on speaker and construction, per and per a do not contrast as consistently as a strict writing chart suggests. Valencian usage generally maintains per a more robustly, and the AVL norm reflects that distinction. In careful IEC-oriented prose, per a què is the clearest explicit purpose question. Regional reduction to per què should not be treated as ignorance, but learners benefit from maintaining the written semantic contrast.
Ambiguous English prompts
“Why did you call?” has no built-in distinction. If the speaker asks about the trigger, write Per què has trucat? An answer could be Perquè he vist la teva nota. If the intended question is “What did you call for?”, the explicit purpose version is Per a què has trucat?, answered perhaps by Per demanar hora. Likewise, “Tell me the reason why” can be a question clause—Digues-me per què ho vas fer—or a noun phrase—Explica'm el perquè de la teva decisió.
Spanish can help only after the meaning is known: its porque, por qué, el porqué, and para qué often run parallel. It can also mislead through automatic spelling transfer or through a dialect's treatment of per/per a. Decide the Catalan syntax first.
Dialogue: one space changes the request
—Per què necessiteu la sala gran? —Perquè la petita ja està reservada. —No preguntava la causa: preguntava per a què la necessiteu. —Perquè hi càpiguen tots els participants.
—Why do you need the large room? —Because the small one is already booked. —I wasn't asking for the cause: I was asking what you need it for. —So that all the participants will fit.
The first answer supplies a prior circumstance. The corrected question requests a goal, and the final perquè introduces that goal with the subjunctive càpiguen.
Correction task
Choose the form and justify it: No sabem no funciona, però el tècnic vol descobrir serveix aquesta peça i _ de l'avaria. The natural answers are per què (embedded question about cause), per a què (question about function), and el perquè (noun governed by descobrir, with de l'avaria).
Common Mistakes
1. Joining the words in a direct question.
❌ Perquè heu tancat abans d'hora?
Incorrect — this is a direct 'why' question, so què is interrogative and must be separate.
✅ Per què heu tancat abans d'hora?
Why did you close early?
2. Splitting the causal conjunction.
❌ Hem marxat per què començava a nevar.
Incorrect — the clause gives an asserted cause and requires the one-word conjunction perquè.
✅ Hem marxat perquè començava a nevar.
We left because it was starting to snow.
3. Using a causal question for an explicit function.
❌ Perquè serveix aquest botó vermell?
Incorrect — a direct purpose question cannot use the one-word conjunction perquè.
✅ Per a què serveix aquest botó vermell?
What is this red button for?
4. Forgetting that the nominal form is a noun.
❌ Ningú no ha explicat el per què del canvi d'horari.
Incorrect in the noun phrase — the lexical noun is written perquè, while el is separate.
✅ Ningú no ha explicat el perquè del canvi d'horari.
Nobody has explained the reason for the timetable change.
5. Using the indicative for an intended outcome.
❌ T'ho envio perquè ho tens abans de la reunió.
Incorrect for the intended meaning — the result is a goal, not an asserted present fact.
✅ T'ho envio perquè ho tinguis abans de la reunió.
I'm sending it to you so that you have it before the meeting.
Key Takeaways
- Write perquè for a causal conjunction and for a purpose conjunction; use context and mood to distinguish them.
- Write per què when què is interrogative or a relative governed by per.
- Write el perquè when the expression behaves as a noun; its plural is els perquès.
- Write per a què to make a purpose or function question explicit, while recognizing genuine regional variation in per/per a.
- Do not choose by English or Spanish spelling alone. Identify cause, goal, question, noun phrase, or relative structure first.
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Start learning Catalan →Related Topics
- Perquè, Ja Que, Com Que, and CarA2 — Choose among Catalan causal connectors according to whether the reason is neutral, already shared, placed first, or presented in a literary explanatory register.
- Purpose ConnectorsA2 — Express intended outcomes with perquè plus the subjunctive and with per tal de, per tal que, and a fi de while tracking who performs each action.
- Question WordsA1 — How to ask for people, things, choices, quantities, manner, time, place, and reasons with Catalan interrogatives and the prepositions they require.
- Questions with PrepositionsA2 — How Catalan keeps required prepositions before qui, què, quin, and on in questions, including purpose, destination, source, and verb government.
- Embedded QuestionsA2 — How Catalan places questions inside statements and larger questions with si or an interrogative phrase, declarative punctuation, and non-inverted word order.
- Purpose Clauses with PerquèB1 — Distinguish purpose perquè with the subjunctive from causal perquè with the indicative, and choose finite or infinitival purpose clauses by subject reference.