One of the most frequent uses of the imperfect subjunctive is in conditional sentences — what linguists call Type 2 si-clauses. These express hypothetical or contrary-to-fact situations in the present. In English, this is "If I had money, I would buy a car" — the speaker does not actually have the money.
The Structure
The pattern is simple and fixed:
Si + imperfect subjunctive, + conditional.
Or, equivalently, you can swap the order:
Conditional + si + imperfect subjunctive.
Compraría una casa si tuviera dinero.
I would buy a house if I had money.
Both versions mean the same thing. Note that when the si-clause comes first, it is separated by a comma.
Type 2 Overview
| Part | Tense | Example |
|---|---|---|
| Condition (si-clause) | Imperfect subjunctive | si tuviera tiempo |
| Result | Conditional | viajaría más |
| Full sentence | — | Si tuviera tiempo, viajaría más. |
When to Use It
Use Type 2 when the condition is:
- Contrary to fact in the present — "If I were you" (I am not you).
- Unlikely or imaginary — "If I won the lottery" (probably will not happen).
- Purely hypothetical — "If horses could fly…"
Si fuera tú, hablaría con ella.
If I were you, I would talk to her.
Si pudiera volar, iría a la luna.
If I could fly, I would go to the moon.
The Critical Rule: Never Present Indicative after Si + Hypothetical
A common mistake is to write "Si tengo dinero, compraría una casa" — mixing present indicative with conditional. This is ungrammatical. In Type 2 sentences, si must be followed by the imperfect subjunctive, never the present indicative.
Comparing Type 1 and Type 2
| Type | Si-Clause | Result | Meaning |
|---|---|---|---|
| Type 1 (real) | Present indicative | Future / present | Real possibility |
| Type 2 (hypothetical) | Imperfect subjunctive | Conditional | Unreal / unlikely |
Si tuviera tiempo, iría al cine.
If I had time, I would go to the cinema.
The first sentence implies the speaker might realistically have time. The second implies the speaker does not have time right now, or that it is unlikely.
Irregular Verbs in Si-Clauses
Because the imperfect subjunctive inherits its irregularity from the preterite, irregular verbs slot right in:
Si supieras la verdad, te sorprenderías.
If you knew the truth, you would be surprised.
Si pudieras elegir, ¿qué harías?
If you could choose, what would you do?
Literary Alternative with Hubiera
In very formal or literary Spanish, the result clause can also use the -ra form of haber:
Si tuviera más tiempo, hubiera terminado el libro.
If I had more time, I would have finished the book.
This mixes Type 2 with a literary conditional perfect. In everyday speech, you would normally say habría terminado.
Next: learn como si, which always uses the imperfect subjunctive, or revisit past triggers.
Related Topics
- Imperfect Subjunctive: -Ra FormsB2 — Learn how to form the imperfect subjunctive using the -ra endings, the most common form in Latin American Spanish.
- Past-Tense TriggersB2 — How the imperfect subjunctive pairs with past-tense main clauses to maintain sequence of tenses.
- Como SiB2 — The expression como si (as if) always requires the imperfect subjunctive, even in present contexts.