- Understand when quisiera and querría are interchangeable
- Apply imperfect subjunctive for polite requests
- Use conditional for hypothetical consequences and past probability
- Avoid the common mistake of conditional after "si"
- Master which contexts require which form
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Extension to: Imperfect SubjunctiveUpper intermediate
Imperfect Subjunctive vs Conditional
When quisiera and querría are interchangeable
The rule at a glance
quisiera = querría, but most verbs can't swap
The -ra form can replace the conditional mainly 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.
- The big mistake: no conditional after si meaning "if". Si tendría dinero is wrong; say Si tuviera dinero.
- The swap is narrow: it works for quisiera, pudiera, debiera (and hubiera), and only with the -ra form: Quisiese un café doesn't work. With other verbs, standard Spanish keeps the conditional: compraría, not comprara.
- Conditional only also for past guesses and reported speech: Serían las tres cuando llegó (it was probably about three when he arrived); Dijo que vendría (he said he would come).
What You'll Learn
Overview
You've learnt that quisiera (imperfect subjunctive) and querría (conditional) both mean "I would like." But when can you use either one, and when must you choose a specific form?
This confusion exists because in some contexts, these forms are completely interchangeable, whilst in others, only one is grammatically correct. Understanding the difference will help you sound more natural and avoid mistakes.
🔗 Grammar Foundation
This article assumes you know how to form both tenses. If you need a refresher:
• Imperfect Subjunctive - formation and main uses
• Conditional Tense - formation and main uses
💡 The Quick Answer
Interchangeable: Polite requests with querer, poder, and similar verbs
Only Conditional: Hypothetical consequences, probability in the past
Only Imperfect Subjunctive: After "si" clauses, after subjunctive triggers, "como si"
Deep Dive
🤝 When They're Interchangeable: Polite Requests
With verbs like querer, poder, and deber, both forms work for polite requests. The imperfect subjunctive is often considered slightly more formal, but both are perfectly acceptable.
Imperfect Subjunctive
Quisiera una mesa para dos
I would like a table for two
Slightly more formal/polite
Conditional
Querría una mesa para dos
I would like a table for two
Also polite, slightly less formal
More Examples (Both Work)
poder: Pudiera/Podría ser verdad (It could be true)
deber: Debieras/Deberías descansar más
Regional note: In Spain, quisiera is very common in polite requests, and hubiera/habría are both everyday. With poder and deber, the conditional (podrías, deberías) is far more usual in speech; pudiera and debiera sound formal or literary.
⚠️ When You MUST Use Conditional
Rule 1: Hypothetical Consequences (Main Clause)
When expressing what would happen in a hypothetical situation:
✓ Correct:
Si tuviera dinero, compraría una casa
If I had money, I would buy a house
✗ Wrong:
Si tuviera dinero, comprara una casa
Cannot use imperfect subjunctive here
Rule 2: Probability in the Past
When speculating about what probably happened:
✓ Serían las tres cuando llegó→ It was probably about three o'clock when he arrived
Rule 3: Future in the Past (Reported Speech)
When reporting what someone said they would do:
✓ Dijo que vendría mañana→ He said he would come tomorrow
🔒 When You MUST Use Imperfect Subjunctive
Rule 1: After "Si" (If) Clauses
In the "if" part of a hypothetical sentence:
✓ Correct:
Si tuviera tiempo, iría al cine
If I had time, I would go to the cinema
✗ Wrong:
Si tendría tiempo, iría al cine
Don't use the conditional after si meaning "if"
⚠️ Common Mistake: English speakers are tempted to say "If I would..." but Spanish never uses the conditional after "si" (if) in hypothetical sentences.
Rule 2: After Subjunctive Triggers
Verbs that trigger the subjunctive require imperfect subjunctive in past contexts:
✓ Quería que vinieras→ I wanted you to come
✓ Dudaba que fuera verdad→ I doubted it was true
📚 Learn more: Subjunctive Trigger Phrases - fixed phrases and expressions that always require the subjunctive
Rule 3: After "Como Si" (As If)
"Como si" always requires imperfect subjunctive, never conditional:
✓ Habla como si fuera un experto→ He speaks as if he were an expert
Examples
✓ BOTH Work (Interchangeable)
Polite request
Quisiera un café / Querría un café
I would like a coffee
Possibility
Pudiera ser verdad / Podría ser verdad
It could be true
Soft advice
Debieras descansar / Deberías descansar
You should rest
→ ONLY Conditional
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 when he arrived
Reported speech
Dijo que vendría mañana
He said he would come tomorrow
→ ONLY Imperfect Subjunctive
After "si"
Si tuviera tiempo, iría al cine
If I had time, I would go to the cinema
After trigger verb
Quería que vinieras
I wanted you to come
After "como si"
Habla como si fuera un experto
He speaks as if he were an expert
Common Mistakes
⚡ The Most Common Mistake
Don't use the conditional after si meaning "if":
✗ Si tendría dinero...
✓ Si tuviera dinero...
When si means "whether", the conditional is fine: No sabía si vendría (I didn't know whether he would come).
🔗 Continue Learning
Now that you understand when to use each form:
• Imperfect Subjunctive - Full conjugation tables and all uses
• Conditional Tense - Complete guide with examples
• Conditional Sentences - Master all types of "si" clauses