Future Time Clauses
In sentences with when, as soon as, before, after, until, or once talking about the future, put the time-clause verb in present simple, not will — save will for the other clause, which describes the actual future action.
Formula
Examples
Common Time Markers
Usage
- •Describing a future plan that depends on another future event
- •Giving instructions or sequencing steps that will happen in order
- •Making promises or predictions tied to a future trigger
- •Talking about a future action with a clear time boundary (until, before, after)
Studying is free forever on Budling — no account needed to try it.
Try 5 cards free — no signup →Do you use will after when, before, after, until?
No — the clause introduced by when, as soon as, before, after, until, or once always takes present simple, even though the meaning is future: "I will call you when I arrive," not "when I will arrive." Only the other clause — the one describing the real future action — keeps will.
Why is "I will call you when I will arrive" wrong?
Native speakers treat the time-clause verb as already anchored to the future event, so adding will there feels redundant — like marking the future twice in one sentence. The trigger word itself (when, once, as soon as) already signals the future, so the verb stays in present simple: "when I arrive," not "when I will arrive."
Do I need a comma when the time clause comes first?
Yes — if the time clause opens the sentence, put a comma before the main clause: "When I arrive, I will call you." If the main clause comes first, no comma is needed: "I will call you when I arrive."
Comparison Table
| Form | Signals | Example |
|---|---|---|
| when | A future trigger point | I will call you when I arrive. |
| as soon as | Immediacy right after the trigger | We will start as soon as everyone arrives. |
| before | A boundary — earlier than | She will text you before she leaves. |
| after | A boundary — later than | He will call after he lands. |
| until | Continues up to a point | They will stay until the music stops. |
| once | Immediacy, emphasis on completion | Once you save it, you can close the app. |
Save this comparison chart
When to Use Future Time Clauses
Trigger then action
We will start the meeting as soon as everyone arrives.
Boundary before a deadline
She will text you before she leaves the office.
Continuing until a future endpoint
They will stay at the party until the music stops.
Save this timeline chart
More Examples
We will start the meeting as soon as everyone arrives.
Trigger event starts the main action
She will text you before she leaves the office.
Time clause sets a boundary before the main event
He is going to study medicine after he finishes school.
"be going to" also pairs with a present-simple time clause
Once you save the document, you will be able to close the app.
"once" stresses immediacy after completion
They will stay at the party until the music stops.
"until" marks the end point of an action
When the rain stops, we will go for a walk.
Time clause first, comma before the main clause
Common Mistakes
- ✗Using will in the time clause: "I will call you when I will arrive." — should be "when I arrive."
- ✗Dropping will from the main clause: "I call you when I arrive." — the main clause still needs will.
- ✗Missing the comma when the time clause starts the sentence: "When I arrive I will call you." — should be "When I arrive, I will call you."
- ✗Confusing until (a boundary in time) with by (a deadline): "I will wait by you arrive." — should be "until you arrive."
Tips
- ✓Spot the trigger word (when, as soon as, before, after, until, once) — that clause always takes present simple, never will.
- ✓The other clause (the one with the real future action) keeps will — only one clause in the sentence uses will.
- ✓If the time clause comes first, put a comma before the main clause: "Before you leave, turn off the lights."
Advanced Notes
Native speakers treat the time-clause verb as already "anchored" to the future event itself, so adding will there feels redundant — like saying "will" twice for one future. The pattern also governs written sequencing in instructions, contracts, and plans ("Once the payment clears, we will ship the order"), and it extends to a matching pair with present perfect for completed prerequisites: "I'll leave after I've finished this email." In casual speech, "once" and "as soon as" both stress immediacy, while "before" and "until" set a boundary rather than a trigger.
FAQ
Why don't we use will after when/as soon as/before/after/until/once?
Because that clause is treated as already tied to the future trigger event — adding will would mark the future a second time in the same sentence. The present simple form covers it: "as soon as everyone arrives," not "as soon as everyone will arrive."
I will call you when I arrive — why not "when I will arrive"?
The time clause ("when I arrive") always uses present simple, even with future meaning. Will only belongs in the main clause — the one stating the actual future action: "I will call you."
I call you when I arrive — is that correct for a future plan?
No — the main clause still needs will to express the future action: "I will call you when I arrive." Dropping will from the main clause is a common mistake; only the time clause loses it.
When I arrive I will call you — do I need a comma?
Yes — when the time clause comes first, add a comma before the main clause: "When I arrive, I will call you." No comma is needed if the main clause comes first: "I will call you when I arrive."
Until vs by — what's the difference?
"Until" marks a continuous boundary in time — an action or state continues up to that point: "I will wait until you arrive." "By" marks a deadline — something happens at or before that point, not continuously up to it: "I will finish by 6 PM." "I will wait by you arrive" is wrong; "until" is what that sentence needs.
Practice
- 1.I will call you when I (arrive).
- 2.We (start) the meeting as soon as everyone arrives.
- 3.She will text you before she (leave) the office.
- 4.They will stay at the party until the music (stop).
- 5.Once you (save) the document, you will be able to close the app.
Compare With
Other B1 Topics
Present Perfect
Used for past actions that still matter or connect to now
Present Perfect Continuous
Used for ongoing actions that started in the past and still continue
Modal Verbs
Expresses ability, obligation, permission, or possibility
Passive Voice (Basic)
Used for sentences where the action or result matters more than who did it
Used To
Used for past habits or states that no longer exist
Future Continuous
Used for actions in progress at a specific future moment
Question Tags
Used for confirming information or seeking agreement at the end of a statement
Linking Words: However, Although, Despite, In Spite Of
Used for connecting contrasting ideas using concession and contrast markers
Relative Clauses (Defining)
Clauses that identify exactly which person, thing, or place you mean.
So and Such
Use so before adjectives/adverbs and such before nouns to emphasize degree, often followed by a that-clause showing the result.
Order of Adjectives
The fixed order adjectives usually follow before a noun: opinion, size, age, shape, colour, origin, material, purpose.
Subject and Object Questions
Who broke it? vs Who did you see? — question word as subject or object.