📖Extension to: Imperfect SubjunctiveUpper intermediate

Imperfect Subjunctive vs Conditional

When quisiera and querría are interchangeable

🎯What You'll Learn

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

📋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: ¿Pudieras/Podrías ayudarme?

deber: Debieras/Deberías descansar más

Regional note: In Spain, you'll hear both equally. In Latin America, the conditional (querría, podrías) is more common in everyday speech.

⚠️ 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

Never use conditional after "si"

⚠️ Common Mistake: English says "If I would have..." but Spanish NEVER uses conditional after "si" 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 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

Polite question

¿Pudieras ayudarme? / ¿Podrías ayudarme?

Could you help me?

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 experto

He speaks as if he were an expert

⚠️Common Mistakes

⚡ The Most Common Mistake

Never use conditional after "si":

✗ Si tendría dinero...

✓ Si tuviera dinero...

🔗 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