In time clauses introduced by when, as soon as, before, after, until, even when referring to the future, use the simple present tense:
我I 会will 打电话call 你you 当...时when 我I 到达arrive.
I'll call you as soon as I arrive.
等Wait 这里here 直到until (冠词)the 雨rain 停stops.
Wait here until the rain stops.
Note Do not use will in time clauses: ~~when I will arrive~~ ✗ → when I arrive ✓.
Common Errors
- ❌ ~~I will meeting him tomorrow.~~ → ✓ I will meet him. / I am meeting him. — will + base verb, be + -ing; these two structures cannot be combined.
- ❌ ~~What will you do tonight?~~ (asking about someone else's arrangement) → ✓ What are you doing tonight? — For asking about established arrangements, the present continuous sounds more natural.
- ❌ ~~I'll go to the dentist tomorrow — I booked it last week.~~ → ✓ I am going to the dentist tomorrow. — For things already scheduled, do not use the spontaneous decision marker will.
- Use Shall for suggestions in questions: Shall we go? (Shall we go?) Shall I open the window? (Shall I open the window?)