Conditionals in English: the five types, with formulas and spoken examples

What conditionals are and how they are built

Cambridge Dictionary explains that conditional sentences consider imagined or uncertain situations and the possible results of these situations. The most common types involve if, and they consist of a conditional clause and a main clause. Cambridge's example: If a lot of people come, we'll have to get extra chairs. Here if a lot of people come is the conditional clause and we'll have to get extra chairs is the main clause.

Oxford Language Club adds that conditionals describe the result of something that might happen (in the present or future) or might have happened but didn't (in the past), and that they are made using different English verb tenses.

You can put the clauses in either order:

• If-clause first (with a comma): If it rains, we'll stay home.
• Main clause first (no comma): We'll stay home if it rains.

To choose the right type, ask: is this situation real and possible, or imagined? The next sections take each type in turn.

Zero conditional: facts and rules

ABC's English lesson says that we use the zero conditional to talk about things that are always true. Oxford Language Club agrees: this conditional is used when the result will always happen. Its example: if water reaches 100 degrees, it always boils. The site adds that the if in this conditional can usually be replaced by when without changing the meaning.

• Formula: If + present simple, present simple.

• If you heat ice, it melts.
• If you press this button, the machine starts.
• When people are tired, they make more mistakes. (if or when)
• I get a headache if I skip lunch. (a general habit)

Use the zero conditional for scientific facts, rules, instructions and general habits, not for one particular situation. Because the result is always true, both verbs are in the present simple.

Speaking tip: in conversation, the zero conditional is how you give advice about how something works. "If it doesn't turn on, hold the button for five seconds."

First conditional: real future possibilities

Use the first conditional for a real possibility in the future, when you think the condition is likely or possible.

• Formula: If + present simple, will + base verb.

• If it rains tomorrow, we'll cancel the picnic.
• If you study hard, you'll pass the exam.
• I'll call you if I finish early.
• If she doesn't call, I'll send her a message.

Two important rules:

1. **Do not use will in the if-clause.** If it will rain is wrong. Use the present simple: If it rains.
2. The main clause can use other modals. If you see him, could you give him this? If it rains, we might stay home. If you're tired, you should rest.

First-conditional sentences are everywhere in daily speech: promises, warnings and plans.

• Promise: If you help me, I'll buy you lunch.
• Warning: If you touch that, you'll get burned.
• Plan: If the train is late, I'll take a taxi.

Cambridge notes other expressions that can replace if in this kind of sentence, such as unless, should and as long as. See the section on those below.

Second conditional: unreal or unlikely situations

Second conditionals describe situations that are unreal or unlikely, in the present or future. You are imagining.

• Formula: If + past simple, would + base verb.

• If I had more time, I would learn Italian. (I don't have more time.)
• If I won the lottery, I'd buy a house. (unlikely)
• If she lived closer, we'd see each other more.
• What would you do if you lost your job?

The past simple here does not mean the past. It shows that the situation is imaginary. Compare:

• If I see him, I'll tell him. (first: it may really happen)
• If I saw him, I'd tell him. (second: it is unlikely or imaginary)

"If I were you": with the verb be, many speakers use were for all persons in the if-clause: If I were you, I'd take the job. If he were here, he'd help. In everyday speech, was is also used (If I was you), but were is the standard form, especially in advice and in formal writing.

Giving advice with the second conditional: If I were you, I'd talk to your manager. This is polite and very common in conversation.

**Use could or might instead of would** for different meanings: If I had a car, I could drive to work. If it stopped raining, we might go out.

Third conditional: the past that did not happen

Third conditionals look back at imagined situations in the past: regrets, criticism and what might have been. The situation can no longer change.

• Formula: If + past perfect, would have + past participle.

• If I had known, I would have called you. (I didn't know, so I didn't call.)
• If she had studied more, she would have passed. (She didn't study, so she failed.)
• We wouldn't have been late if we had left earlier.
• If they hadn't cancelled the flight, we would have arrived on time.

Variations: use could have or might have for other meanings.

• If I had had the money, I could have bought it. (ability)
• If you had asked, I might have helped. (possibility)

**Do not use would have in the if-clause.** If I would have known is a common mistake in learners' English and in some informal speech. In standard English, write If I had known.

Spoken forms: in conversation, the third conditional is heavily contracted. If I'd known, I'd have called sounds like "If I'd known, I'd've called". We discuss these below.

Third-conditional sentences are very useful in job interviews when you talk about mistakes you learned from: If I had planned the project better, we would have finished on time. Now I plan carefully. See our guide to situational interview questions for more.

Mixed conditionals: when the time changes

A mixed conditional combines two different times, usually a condition in the past with a result in the present, or the reverse. Here are two examples, as Scribbr gives them:

• Past condition, present result: If you had eaten your dinner, you wouldn't be hungry. (You didn't eat, so now you are hungry.)
• Present condition, past result: If you paid attention in school, you would have learned more. (You didn't pay attention in general, so you didn't learn.)

Formulas

• Past → present: If + past perfect, would + base verb.

If I had taken the job, I would be rich now.

• Present → past: If + past simple, would have + past participle.

If I were braver, I would have said something.

Mixed conditionals are less common but very natural for regrets about something that still affects you. Ask yourself: When was the condition? When is the result?

If you find mixed conditionals difficult, build them from the two simple types you already know: take the if-part from the third conditional and the main-clause from the second conditional.

Other words: unless, as long as, provided that, in case, even if

You do not always need if. Cambridge lists other expressions that make conditionals, among them unless, should and as long as, and gives the example: Unless you book weeks in advance, you won't get a flight.

Two warnings:

• Unless already means if not. Do not add another negative: Unless you don't hurry is wrong. Say Unless you hurry.
• In case is not the same as if. If it rains, I'll take a taxi means I will take a taxi only when it rains. I'll take an umbrella in case it rains means I take an umbrella now, as a precaution.

Formal inversion: in formal English, you can drop if and invert the subject and verb: Should you need help, please call me. Had I known, I would have called. Were I you, I would accept. These sound formal, and are common in business writing.

How conditionals sound in speech

Natural speech uses contractions and weak forms. If you say every word clearly, you will sound stiff and may not understand fast speakers.

• I'd can mean I would or I had. Context tells you which: If I'd known (had), I'd call you (would).
• would have becomes would've ("woulda"): I would've called.
• If I had known, I would have called is usually spoken as "If I'd known, I'd've called."
• won't (will not) and wouldn't (would not) sound similar. Listen for the vowel: won't has "oh", wouldn't has a short "oo".

In writing, never write would of; write would have. For more on how these small words sound, see our guides to contractions in English and the schwa sound.

If you practise only one habit, say a few conditionals aloud every day, in your own words: "If I had more time, I'd exercise more." The pattern becomes automatic when your mouth knows it.

Common mistakes and a quiz

Mistakes

• Wrong: If it will rain, we will stay home. Right: If it rains, we will stay home.
• Wrong: If I would have time, I would help. Right: If I had time, I would help.
• Wrong: If I would have known, I would have called. Right: If I had known, I would have called.
• Wrong: If I am you, I would go. Right: If I were you, I would go.
• Wrong: You won't pass unless you don't study. Right: You won't pass unless you study.
• Wrong: If you will help me, I will be grateful. Right: If you help me, I will be grateful. (If you will is only used for polite requests: If you will wait here, I'll get the manager.)

Quiz: Complete with the correct form.

1. If I (have) more money, I (buy) a bigger flat.
2. If it rains tomorrow, we (stay) at home.
3. If you (heat) water to 100 degrees, it boils.
4. If she (study) harder, she would have passed.
5. If I (be) you, I would apologise.
6. I (call) you if I finish early.
7. If they hadn't missed the bus, they (arrive) on time.

Answers: 1. had / would buy. 2. will stay. 3. heat. 4. had studied. 5. were. 6. will call. 7. would have arrived.

For more speaking practice, see our guide to English speaking practice, where an AI tutor can play a conversation and notice if a conditional goes wrong.