Imperfect subjunctive vs conditional
Quisiera and querría both mean "I would like", but the swap is narrow: most verbs need the conditional for "would" and the subjunctive after si.
The rule at a glance
quisiera = querría, but most verbs can't swap
Only with querer, poder, deber and haber; hubiera dicho = habría dicho
Both work: querer, poder, deber
quisiera = querría
I would like
Quisiera un café, por favor.
I'd like a coffee, please. (Querría also works.)
Only conditional: the "would" result
compraría
I would buy
Si tuviera dinero, compraría una casa.
If I had money, I'd buy a house.
Only subjunctive: si (if) + something imaginary
tuviera
I had
Si tuviera tiempo, iría al cine.
If I had time, I'd go to the cinema.
Only subjunctive: after como si
fuera
he were
Habla como si fuera un experto.
He talks as if he were an expert.
Which form?
In some contexts the imperfect subjunctive (quisiera) and the conditional (querría) are completely interchangeable; in others only one is grammatically correct. This page assumes you know how to form both tenses.
| Form | Used for | Example |
|---|---|---|
| Both (interchangeable) | Polite requests and soft advice with querer, poder, deber (and haber) | Quisiera / Querría un café |
| Only the conditional | Hypothetical consequences, probability in the past, future in the past (reported speech) | Si tuviera dinero, compraría una casa |
| Only the imperfect subjunctive | After si (if) clauses, after subjunctive triggers, after como si | Si tuviera tiempo, iría al cine |
When to use it
1. Both work: polite requests and soft advice
With querer, poder and deber, both forms work. The imperfect subjunctive is often considered slightly more formal, but both are perfectly acceptable. The swap only works with the -ra form (Quisiese un café doesn't work), and with other verbs standard Spanish keeps the conditional: compraría, not comprara.
Imperfect subjunctive: Quisiera una mesa para dos. I would like a table for two (slightly more formal).
Conditional: Querría una mesa para dos. I would like a table for two (also polite).
Possibility: Pudiera ser verdad. / Podría ser verdad. It could be true.
Soft advice: Debieras descansar. / Deberías descansar. You should rest.
2. Only the conditional
For what would happen in a hypothetical situation (the main clause), for guesses about the past, and for what someone said they would do.
Hypothetical result: Si tuviera dinero, compraría una casa. If I had money, I would buy a house.
Past probability: Serían las tres cuando llegó. It was probably about three o'clock when he arrived.
Reported speech: Dijo que vendría el lunes. He said he would come on Monday.
3. Only the imperfect subjunctive
In the "if" part of a hypothetical sentence, after a verb that triggers the subjunctive in a past context, and always after como si (as if).
After si (if): Si tuviera tiempo, iría al cine. If I had time, I would go to the cinema.
After a trigger verb: Quería que vinieras. I wanted you to come.
After a trigger verb: Dudaba que fuera verdad. I doubted it was true.
After como si: Habla como si fuera un experto. He speaks as if he were an expert.
Trigger verbs and phrases are listed in subjunctive trigger phrases and the full list of subjunctive triggers.
Common mistakes
No conditional after si meaning "if"
Not this (incorrect): Si tendría tiempo, iría al cine.
But this (correct): Si tuviera tiempo, iría al cine. – If I had time, I would go to the cinema. English speakers are tempted to say "If I would...", but Spanish never uses the conditional after si (if) in hypothetical sentences.
The result clause takes the conditional
Not this (incorrect): Si tuviera dinero, comprara una casa.
But this (correct): Si tuviera dinero, compraría una casa. – If I had money, I would buy a house. You cannot use the imperfect subjunctive for the "would" result with ordinary verbs.
Quick check
6 questions1. Si ___ más tiempo, aprendería japonés.
After si (if) in a hypothetical sentence: imperfect subjunctive.
2. Si tuviera dinero, ___ un coche nuevo.
The "would" result takes the conditional.
3. ___ un vaso de agua, por favor. (polite: "I would like")
Only the -ra form can replace querría.
4. Mi madre quería que yo ___ médico.
Querer que in the past triggers the imperfect subjunctive.
5. Dijo que ___ a las ocho. (he said he would arrive)
Future in the past (reported speech): conditional.
6. Me miró como si no me ___.
Como si always takes the imperfect subjunctive.
Conditional or imperfect subjunctive? Pick the form that fits.
Going further
Regional use, haber, and si meaning "whether"
Regional note
In Spain, quisiera is very common in polite requests, and hubiera/habría are both everyday: hubiera dicho = habría dicho (I would have said). With poder and deber, the conditional (podrías, deberías) is far more usual in speech; pudiera and debiera sound formal or literary.
When si means "whether"
The no-conditional rule is only for si meaning "if". When si means "whether", the conditional is fine: No sabía si vendría (I didn't know whether he would come). All the types of si clause are in conditional sentences.