Overview
Time clauses are introduced by subordinating conjunctions: when, while, before, after, until, as soon as, once, by the time, whenever. They express the timing of one event relative to another. In future meaning, the time clause uses the present simple even though the meaning is future.
Time clause connectors
- whenWhen I arrived, the meeting had started.
- whileShe was reading while he cooked.
- as soon asI'll call you as soon as I arrive.
- untilI waited until the doors opened.
- before/afterShe prepared before the interview. / He left after finishing.
Tense rule: Future time clauses
- After time connectors, use present simple (NOT 'will') for future meaning:
- ✅ I'll call you when I get home. (not 'will get')
- ✅ As soon as she arrives, let me know. (not 'will arrive')
Common Mistakes
- ❌ I will call you when I will arrive. → ✅ when I arrive.
- ❌ As soon as he will leave, call me. → ✅ As soon as he leaves.
- ❌ Before to leave, turn off the lights. → ✅ Before leaving, turn off the lights.
When to use
Making plans
I'll email you as soon as I arrive.
Storytelling
When she opened the door, she was surprised.
Instructions
Before sending, check all attachments.
Academic writing
After data collection was complete, analysis began.