When vs Ifin Future
Time clauses
CEFR Pathway · You are here
Get talking · Section 1
5 minWarm up
Which is more certain: 'When I get home...' or 'If I get a promotion...'? Why?
Name one thing that will definitely happen this week and one that might happen.
Tell your partner what you'll do as soon as this lesson finishes.
Grammar focus · Section 2
8–10 minWhen vs If — certain vs possible future
We use WHEN for future events we're sure will happen — only the time is uncertain: 'When I get home, I'll cook dinner' (I'm definitely going home).
→ When I finish work, I'll call you. (certain — I will finish work)
→ If I finish early, I'll call you. (not certain — I might not finish early)
→ As soon as she arrives, we'll start.
→ I won't leave until you get here.
More detail
We use IF for future events that may or may not happen: 'If I get a promotion, I'll celebrate' (not certain). Other time clauses — as soon as, before, after, until — also use present simple for the future, never 'will'.
Time clause + present simple, will + infinitive
e.g. When I finish, I'll call you.
When to use
- WHEN: certain future events, just the time is unknown.
- IF: possible/uncertain future events.
- AS SOON AS: immediately after something happens.
- BEFORE / AFTER / UNTIL: future time relationships.
| Word | Certainty | Example |
|---|---|---|
| When | Certain to happen | When I get home, I'll relax. |
| If | Might not happen | If I get home early, I'll relax. |
No 'will' in the time clause
NOT 'When I will finish...' Say 'When I finish...'
Memory tip
Ask yourself: is this 100% happening (when) or maybe (if)?
Natural English
'As soon as' emphasises speed — use it for quick reactions: 'I'll text you as soon as I land.'
Question 1.____ I get home, I'll cook dinner. (certain)
Question 2.____ I win the lottery, I'll travel the world. (uncertain)
Question 3.As soon as she ____, we'll start.
Question 4.I won't leave until you ____.
Question 5.____ I finish this course, I'll be fluent. (certain — it's planned)
Build the sentence → spot the natural chunks → say it aloud → reply like a real conversation.
1.Rebuild the sentence — then say it aloud.
2.Rebuild the sentence — then say it aloud.
3.Rebuild the sentence — then say it aloud.
Vocabulary · Section 3
5–7 minWords & phrases to own
Don't just read these — say one out loud, then use it about your life.
definite
certain, sure
"It's definite — I'm starting the new job."
Name something definite in your future.
uncertain
not sure
"It's uncertain if it'll rain."
Name something uncertain about next month.
as soon as possible (ASAP)
immediately, without delay
"I'll reply ASAP."
What will you do ASAP after class?
eventually
in the end, after some time
"We'll get there eventually."
Something that will happen eventually.
to arrange
to plan/organise
"I'll arrange a meeting when he's free."
Something you need to arrange soon.
meanwhile
at the same time
"I'll cook; meanwhile, you can set the table."
Use 'meanwhile' in a sentence.
Discuss with a partner
- →What's definite in your plans this month? What's uncertain?
- →What will you arrange when you have more free time?
Finish the sentence about you
- When I..., I'll... …
- If I..., I'll... …
- As soon as..., I'll... …
60-second write
Write 3 sentences: one with 'when', one with 'if', one with 'as soon as'.
Pronunciation · Section 4
3–4 minStress on time-clause connectors
- • When I get home, I'll relax.
- • If I have time, I'll help.
- • As soon as it starts, tell me.
- • I'll wait until you're ready.
How to say it
Connectors like 'when', 'if', 'as soon as', 'until' carry light stress but the whole clause should flow together without pausing after the connector. Practise saying the clause as one breath group before the comma.
Reading · Section 5
8–10 minTwo very different plans
Leo has a clear plan for after graduation. When he finishes university in June, he'll move to Berlin — his cousin already has a room for him. As soon as he arrives, he'll start job-hunting in tech, since he has a few contacts there already. His sister Nadia's future looks less certain. If she gets accepted onto the exchange programme, she'll spend a year in Canada. If she doesn't, she'll stay and finish her degree at home instead — either way is fine with her. 'When I know the result, I'll tell you straight away,' she told Leo last week. Until then, she's trying not to think about it too much, though it's hard when something so big depends on one letter in the post.
Read carefully, then answer the detail questions. Underline the words in the text that gave you each answer.
Question 1.What is certain about Leo's plan?
Question 2.What is uncertain for Nadia?
Question 3.What will Nadia do if she isn't accepted?
Q1.Leo's move to Berlin is certain.
Q2.Nadia is sure she'll go to Canada.
Q3.Nadia will tell Leo the result as soon as she knows.
Listening · Section 6
8–10 minPlanning the evening
Listening audio
Tap play to listen. Replay as many times as you need.
Show transcript
Tom:When I finish work, I'll pick up some food on the way home.
Ella:Good idea. If they still have that pasta, get some for me too.
Tom:Will do. As soon as I'm out, I'll message you.
Ella:Perfect. I won't start cooking until I hear from you.
Tom:And if the shop's closed, I'll just order a pizza instead.
Ella:Either way works for me — when you're home, we'll eat.
Listen once for the whole picture, then again for the details before you answer.
Question 1.What will Tom do when he finishes work?
Question 2.What will Ella do until she hears from Tom?
Question 3.What will Tom do if the shop's closed?
Exam skills · Section 7
5 minCambridge PET — Use of English (choosing connectors)
Task
Choose the correct connector (when/if/as soon as/until) in gapped sentences.
Strategy
First decide: is the event certain or uncertain? Certain → when/as soon as/until. Uncertain → if. Then check the tense: never 'will' straight after the connector — always present simple.
Example
'____ I graduate, I'll start job-hunting' → certain event → 'When I graduate...'
Practice · Section 8
8–10 minFill in the blank
Question 1.____ I get home, I'll relax. (certain)
Question 2.____ it rains, we'll cancel. (uncertain)
Question 3.As soon as he ____, tell him the news.
Question 4.I'll wait ____ you're ready.
Question 5.____ I finish my degree, I'll travel. (planned, certain)
Q1.Write a sentence with 'when' about something certain in your future.
Q2.Write a sentence with 'if' about something uncertain.
Q3.Write a sentence with 'as soon as'.
Writing · Section 9
5 minPut it in writing
Write your own version first, then open the model and compare — what would you change?
Your task
Write 100 words describing your plans for after this course, using 'when', 'if', and 'as soon as' at least once each.
Compare with the model
When I finish this English course, I plan to take the official exam straight away, while everything is still fresh. As soon as I get the result, I'll decide on my next step. If I pass with a good score, I'll look for a job that requires English communication. If I don't get the score I want, I'll take a few more months to practise and try again later in the year. Either way, when I have more confidence speaking, I'd like to travel somewhere I can only use English — probably the UK or Ireland — to really test what I've learned.
Speaking · Section 10
10–15 minMake it a real conversation
CERTAIN vs UNCERTAIN · In pairs, one student says a future event; the partner must correctly ask 'when' (if certain) or 'if' (if uncertain), then answer using the appropriate word.
Useful phrases
- • When are you going to...?
- • Do you know if...?
- • When I..., I'll...
- • If I..., I'll...
Role-play & swap
Role-play the scenario once. Then swap roles and change two details so the second run is not a repeat.
- AWhat will you do when you finish work today?
- B_______________
- AAnd if it's raining?
- B_______________
Optional · Teacher-led
Teacher Activities
This is a subtle but high-value distinction — spend extra time on certainty vs possibility before drilling forms. ~28 min total
Homework · Section 11
Take-homeTake it home
Write 5 sentences correctly choosing 'when' or 'if'.
Record yourself describing 3 certain plans (when) and 2 uncertain ones (if).
Find 2 examples of 'as soon as' or 'until' in an English text.
Recap · Section 12
2–3 minWhat you've learned
- WHEN = certain future event; IF = possible/uncertain event.
- As soon as, before, after, until also take present simple for future.
- Never use 'will' straight after these time-clause connectors.
- Choosing the right connector shows precision, not just grammar accuracy.
- This distinction is a classic exam and real-life communication point.
Extra Practice
Grammar · Vocabulary · Speaking · Review
Found this lesson tricky? Practise the language from Lesson 33 again.
Finished this lesson?
Mark it complete to save it to your progress.