Time clauses with quando, enquanto and assim que

In brief

Use quando (when) to locate an event in time, enquanto (while) for events happening at the same time, and assim que (as soon as) for something that follows immediately. These words connect a time clause to a main clause.

Form

Time clause with quando / enquanto / assim que + main clause, or main clause + time clause. For an anticipated future event after quando or assim que, use the future subjunctive in the time clause, not the simple future.

Usage

• Use quando for a particular occasion or a recurring time relationship; the verb form depends on whether you mean past, present, or future.
• Use enquanto to emphasize that two activities overlap in time.
• Use assim que when the second event happens right after the first.

Examples

• Quando cheguei em casa, minha irmã estava cozinhando. — When I got home, my sister was cooking.
• Enquanto você prepara o café, eu arrumo a mesa. — While you make the coffee, I’ll set the table.
• Quando você chegar, me avise. — When you arrive, let me know.
• Assim que a reunião terminar, eu te ligo. — As soon as the meeting ends, I’ll call you.

Common mistake

❌ Assim que a reunião terminará, eu te ligo.

✅ Assim que a reunião terminar, eu te ligo.

For a future event introduced by assim que, use terminar (future subjunctive), not terminará (simple future).

Remember

The time clause can come before or after the main clause. Enquanto highlights overlap; assim que highlights what happens next.