The five conditionals at a glance
| Type | If clause | Result clause | Use |
|---|---|---|---|
| Zero | present simple | present simple | always true: facts and rules |
| First | present simple | will + verb | a real possibility in the future |
| Second | past simple | would + verb | imaginary now, or unlikely in the future |
| Third | past perfect | would have + V3 | imaginary past: it did not happen |
| Mixed | past perfect | would + verb | a past condition with a result now |
Zero conditional
If + present simple, … present simple
Facts, scientific truths, rules and instructions. Here if means when or whenever.
- If you heat ice, it melts.
- If a soldier is late for formation, the sergeant reports it.
- If the alarm sounds, leave the building immediately.
The result can be an order (an imperative): "If you feel sick, tell the medic."
First conditional
If + present simple, … will / can / may / might + verb
A real possibility in the future and its likely result.
- If it rains tomorrow, we will cancel the field exercise.
- If you study every day, you will pass the ECL.
- We may arrive late if the traffic is heavy.
Common mistakes
- ✗Wrong: If it will rain, we will stay inside.✓Right: If it rains, we will stay inside.
Second conditional
If + past simple, … would / could / might + verb
An imaginary situation now, or a future that is unlikely.
- If I had more time, I would learn Chinese.
- If I were you, I would accept the assignment.
- What would you do if you found a wallet on the street?
With be, formal and test English use were for every person: "If he were here…", "If I were you…". If I was is common in conversation, but choose were on the test.
Common mistakes
- ✗Wrong: If I would have money, I would buy a car.✓Right: If I had money, I would buy a car.
Third conditional
If + past perfect, … would have / could have / might have + V3
An imaginary past: something that did not happen and its imaginary result. Often used for regrets and criticism.
- If we had left earlier, we would have caught the plane. (We didn't leave early.)
- If he had checked the oil, the engine wouldn't have failed.
- She could have passed if she had studied harder.
Common mistakes
- ✗Wrong: If I would have known, I would have come.✓Right: If I had known, I would have come.
Mixed conditionals
Past condition, present result
If + past perfect, … would + verb
Something different in the past would change the situation now.
- If I had taken that job, I would be in Japan now.
- If he hadn't failed the course, he would be a sergeant today.
Present condition, past result
If + past simple, … would have + V3
A permanent situation explains an imaginary past result.
- If she were afraid of heights, she wouldn't have joined the paratroopers.
Unless, provided that, in case and other condition words
| Word | Meaning | Example |
|---|---|---|
| unless | if… not | We'll start at 0700 unless it rains. (= if it doesn't rain) |
| as long as, provided (that), providing | only if | You can borrow the jeep as long as you return it by six. |
| in case | as a precaution, because it might happen | Take a jacket in case it gets cold. |
| otherwise | if not | Hurry up. Otherwise, we'll miss the bus. |
| even if | it does not matter if | I'll finish the report even if I have to stay late. |
| suppose, supposing, what if | imagine that | Suppose you lost your passport. What would you do? |
| but for + noun | if it were not for / if it had not been for | But for the radio, we would have been lost. |
ECL tipIn case is not the same as if. "Take an umbrella in case it rains" means take it now, as a precaution. "Take an umbrella if it rains" means take it only when it rains.
Common mistakes
- ✗Wrong: Unless you don't hurry, you will be late.✓Right: Unless you hurry, you will be late.
Formal inversion: Should you…, Were I…, Had I…
In formal English (orders, reports, letters), if can be dropped. The auxiliary then moves before the subject.
| Normal | Inverted (formal) |
|---|---|
| If you need help, call the duty officer. | Should you need help, call the duty officer. |
| If I were in your position, I would refuse. | Were I in your position, I would refuse. |
| If we had known, we would have helped. | Had we known, we would have helped. |
Common mistakes
- ✗Wrong: Had I knew, I would have told you.✓Right: Had I known, I would have told you.
Wish and if only
| A wish about… | Form | Example |
|---|---|---|
| the present | wish + past simple (were for be) | I wish I spoke better English. · I wish I were taller. |
| the past (a regret) | wish + past perfect | I wish I had studied harder last year. |
| someone's behavior, a change you want | wish + would + verb | I wish you would stop talking during the briefing. |
| an ability | wish + could + verb | I wish I could swim. |
If only takes the same forms and is stronger: "If only I had listened to the instructor!"
Use hope, not wish, for things that are possible: "I hope you pass the test."
Quick check
Choose an answer: the explanation appears straight away.
1If I ___ you, I would talk to the commander.
2If the convoy ___ on time, we would have reached the camp before dark.
3___ you need more information, please contact the duty office.
4Take your rain gear ___ it rains during the march.
5I wish I ___ to the briefing yesterday.
6If you heat water to 100 °C, it ___.
More practice: sample questions on this topic, with answers.
All 39 questions on this topic, in a new order each time.