Imperfect subjunctive: yo trabajara / yo trabajase...

What is the imperfect subjunctive?

The imperfect subjunctive in Spanish talks about uncertain, hypothetical or desired situations in the past.

• It often appears after que or in si-clauses.
• English usually uses "I wanted you to…", "if he did…", "as if it worked".
• Spanish uses one clear form: imperfecto de subjuntivo.

There are two correct sets of endings: -ra and -se. Meaning and use are the same.

• -ra forms = more common in everyday Spanish.
• -se forms = more formal / literary.

Step 1 – How to form it (mechanical rule)

Always start from the 3rd person plural (ellos) of the preterite (indefinido).

1. Take ellos (indefinido).
   • trabajaron, supieron, vinieron
2. Remove -ron.
   • trabaja-, supie-, vinie-
3. Add the imperfect subjunctive endings -ra or -se.

Key idea: if you know ellos (indefinido), you can always create the imperfect subjunctive.

Step 2 – Endings you must know (all verbs)

The endings are the same for -ar, -er, -ir verbs.

Important: in nosotros you always add an accent on the vowel before -ramos / -semos:

• trabajáramos, supiéramos, viniéramos
• trabajásemos, supiésemos, viniésemos

Step 3 – When do we use it?

You already know the subjunctive in the present. The imperfect subjunctive is the same idea, but in the past.

• After past verbs of desire, emotion, doubt, influence:
  • Quería que trabajaras desde casa. (I wanted you to work from home.)
  • Me molestó que no vinieran a la reunión.
• After expressions like “era posible que…”, “era importante que…”:
  • Era importante que todos llegaran a tiempo.
  • Era imposible que el sistema viniera de nuevo después de ese fallo.
• In si-clauses with hypotheses about the present or future (unreal or unlikely):
  • Si el servidor se bloqueara, perderíamos datos.
  • Si tuviera más tiempo, aprendería a usar mejor este programa.
• After “como si” (as if):
  • Hablábamos como si todo funcionara perfectamente.
  • Actúan como si no existiera el problema.
• After “que” when you describe a searched / non‑existent person or thing in the past:
  • Buscaban a alguien que supiera configurar la red.
  • No conocía a nadie que pudiera ayudarme.

Step 4 – -ra or -se: which should I choose?

For meaning, -ra = -se. Both are correct.

• Si el servidor se bloqueara, perderíamos datos.
• Si el servidor se bloquease, perderíamos datos.

In practice:

• Use -ra forms by default (most common in speech and writing).
• Recognize -se forms when reading formal texts, literature, older documents.

Typical learner doubts and mistakes

• 1. Confusing with the imperfect indicative
  • Si el sistema venía,... → habitual past.
  • Si el sistema viniera,... → hypothetical, unreal.
  • Tip: if you mean hypothesis, wish, doubt, you almost always need the subjunctive.
• 2. Forgetting to go via “ellos (indefinido)”
  • Si teniera tiempo… ✗ (invented form)
  • Correct:
    • ellos tuvieron → tuvie- → si tuviera tiempo…
  • Tip: irregular stems follow the indefinido, not the infinitive.
• 3. Missing the accent in nosotros
  • Si nosotros trabajaramos más… ✗
  • Si nosotros trabajáramos más… ✓
  • Rule: in nosotros the vowel before -ramos / -semos always carries an accent.
• 4. Using present subjunctive after a past main verb
  • Quería que vienes / a la reunión. ✗
  • Quería que vinieras a la reunión. ✓
  • Sequence of tenses: past verb in main clause → imperfect subjunctive in the dependent clause.

Mini procedure: decide if you need imperfect subjunctive

Use this quick checklist:

1. Is the main verb in the past?
   • Examples: quería, me gustó, era importante, buscaban, fue necesario…
2. Does it express wish, emotion, doubt, evaluation, hypothesis, or an unreal condition?
   • After que, si, como si etc.
3. Answer “yes” to 1 and 2?
   • → You almost certainly need the imperfect subjunctive.

Then form it mechanically:

1. Take ellos (indefinido).
2. Remove -ron.
3. Add -ra endings (or -se if you prefer).

Self‑check: can you do these?

• Formation
  • Can you form: ellos (indefinido) → stem → yo, tú, nosotros in imperfect subjunctive for:
    • tener, poder, hacer, decir?
• Use
  • Can you complete these mentally?
    • Quería que tú ______ (participar) más en las reuniones.
    • Si el servidor ______ (caerse), ¿qué haríais?
    • Hablábamos como si todo ______ (funcionar) perfectamente.
• Recognition
  • When you see forms like trabajase, supieran, viniésemos, can you identify them as imperfect subjunctive?

If you can answer these without checking the table, you have a solid working control of the imperfect subjunctive.