Zero & First Conditionals + Future Time Clauses
B1 Upper-Intermediate
Forms • Uses • Signals
At a glance
| Structure | Form (if/time clause → result/main clause) | Meaning | Example |
|---|---|---|---|
| Zero conditional | present (any) → present (any) | General truths, rules, what always happens | If water reaches 100°C, it boils. |
| First conditional | present (any) → will + V1 / modal / imperative | Real future possibility in a specific situation | If you study, you’ll pass. |
| Future time clauses | when/after/until/… + present (or pres. perfect) → future form | Time reference for future events | When you arrive, I’ll call. |
Comma rule: place a comma after the if/time clause when it comes first: If it rains, we’ll stay in. No comma if the main clause comes first: We’ll stay in if it rains.
Zero conditional — form & use
- Form If/When + present → present (simple/continuous/perfect).
- Meaning facts, routines, cause–effect rules, instructions.
- Examples If the milk smells bad, I don’t drink it. • If people are talking, I can’t concentrate. • When the light turns red, stop.
- Variant imperatives as results: If the alarm rings, leave the building.
When can often replace if with no change in meaning for general truths.
First conditional — form & use
- Form If + present → will + V1 / be going to / modal (can, may, might, should) / imperative.
- Examples If he doesn’t call, tell me immediately. • If you help me, I’ll finish by Friday. • If you come early, we can grab coffee.
- No will in the if-clause: ✔ If you need me… ✖ If you will need me…
- Special polite use willingness: If you’ll wait here, I’ll fetch the manager. (=if you are willing to)
Useful connectors in real conditions
| Connector | Meaning / notes | Model |
|---|---|---|
| unless | “except if”; avoid double negatives | I won’t go on holiday unless I save some money. (= if I don’t save, I won’t go) |
| as long as / provided (that) / on condition that | strong condition / requirement | You can borrow the car as long as you fill the tank. |
| in case | for prevention/precaution; not the same as if | I’ll take an umbrella in case it rains. (I take it whether it rains or not) |
| if + imperative | instructions | If you see a mistake, tell me. |
Zero vs First — choose the right lens
- General rule If you don’t use oil, it tastes awful.
- Specific occasion If you don’t use oil, it will taste awful.
Future time clauses — the golden rule
- After time words when, as soon as, until, once, before, after, while, by the time → use a present form to talk about the future (not will).
- Examples I’ll go to bed as soon as I finish. • I won’t leave until you arrive. • When I’m 65, I’ll retire.
- Present perfect for completion emphasises finishing before the future point: I’ll go to bed as soon as I have finished. • I won’t leave until you have arrived.
- By the time often pairs with future perfect in the main clause: By the time you get home, I’ll have cooked.
Comma rule matches conditionals: When I am 65, I will retire. • I will retire when I am 65.
Patterns you can copy
| Pattern | Model sentence |
|---|---|
| If + present simple, will + V1 | If you hurry, you’ll catch the bus. |
| If + present perfect, will + V1 | If you’ve finished, we’ll start. |
| If + present, modal (can/may/should) | If it rains, we can stay in. |
| When/after + present, will + V1 | After you arrive, we’ll eat. |
| By the time + present perfect, will have + V3 | By the time he gets back, she’ll have finished. |
Common pitfalls to avoid
- ❌ When I will finish, I’ll call. → ✔ When I finish, I’ll call.
- ❌ If you will help me, I’ll finish. (normal condition) → ✔ If you help me… (will only for willingness: If you’ll help…)
- ❌ Confusing if and in case: precaution ≠ condition.
- ❌ Double negatives with unless: *Unless you don’t call* → ✔ Unless you call… / If you don’t call…
Exercises:
Zero & First Conditionals + Future Time Clauses
Complete the sentences with a time expression from the list.
WORD BANK:
when
whenever
as soon as
until
before
after
once
while
by the time
unless
if
in case
1
I’ll text you
I get through security.
2
Take some cash
the card machine doesn’t work.
3
We’ll stay here
the rain stops.
4
She usually reads the news
she’s on the train.
5
it snows here, the airport closes runways.
6
Send me the file
you finish the draft.
7
He won’t join us
he finishes his report.
8
We’ll book the tickets
I get paid.
9
Let’s grab coffee
the meeting starts.
10
we arrive, the restaurant will probably be full.
Zero & First Conditionals + Future Time Clauses
Choose the correct option. In two of the sentences, there are two possible correct options.
1
We’ll leave as soon as you ______ dinner. Choose TWO correct options
A.
B.
C.
2
By the time you get here, I ______ the report.
A.
B.
C.
3
When you arrive, we ______ in the garden.
A.
B.
C.
4
If water reaches 100°C, it ______.
A.
B.
C.
5
If you don’t hurry, you ______ the bus.
A.
B.
C.
6
I’ll call you as soon as I ______ the news. Choose TWO correct options
A.
B.
C.
7
Unless it ______ tomorrow, we’ll go hiking.
A.
B.
C.
8
After she ______ her exam, she’ll take a break.
A.
B.
C.
9
If my boss calls while I ______ lunch, tell her I’ll ring back.
A.
B.
C.
10
We’ll start the meeting once everyone ______.
A.
B.
C.
Zero & First Conditionals + Future Time Clauses
Complete these sentences with the correct forms of the verbs in brackets. Do NOT use contracted forms
1
If you (heat) ice, it (melt).
2
When I (finish) this report, I (send) it to you.
3
If it (rain) tomorrow, we (cancel) the picnic.
4
Unless you (wear) a helmet, you (not/ride) the motorbike.
5
As soon as she (get) home, she (call) you.
6
Before the guests (arrive), we (clean) the kitchen.
7
If you (not/water) the plants, they (die).
8
I (stay) here until the rain (stop).
9
After we (book) the tickets, we (choose) the seats.
10
If I (see) Mark this evening, I (ask) him about the job.