English grammar · Grammar

Conditionals: Formula, Uses and Exercises

Everything you need to use conditionals correctly: the formula, when to use it, signal words, common mistakes and exercises with answers.

Quick answer

Conditional sentences state the result that follows from a given condition. Type 0 - facts and general rules: If + S + V (present), S + V (present); Type 1 - possible now or in the future: If + S + V (present), S + will + V; Type 2 - contrary to fact (present): If + S + V (past), S + would + V; Type 3 - contrary to fact (past): If + S + had + V3, S + would have + V3. Signal words: if, unless (= if not), provided that, as long as, in case, even if.

Conditionals formula

FormStructureExample
Type 0 - facts and general rulesIf + S + V (present), S + V (present)
Used when the condition is always true, as with facts and science
If you heat water to 100°C, it boils.
'if' can be replaced by 'when' here
Type 1 - possible now or in the futureIf + S + V (present), S + will + V
A condition that really could happen
If it rains, I will stay home.
The if clause takes the present simple, never 'will'
Type 2 - contrary to fact (present)If + S + V (past), S + would + V
A supposition contrary to present fact. With 'be', use 'were' for every person
If I were rich, I would travel the world.
If I were, not 'If I was', in formal style
Type 3 - contrary to fact (past)If + S + had + V3, S + would have + V3
A supposition contrary to what actually happened in the past
If I had studied, I would have passed the exam.
Used for regret about the past - 'if only...'

How to use conditionals

1. Type 0: general truths

Describes a law of nature or something that is always true

If you mix red and blue, you get purple.

2. Type 1: it really could happen

A condition that really could happen now or in the future

If you don't hurry, you will miss the bus.

3. Type 2: untrue in the present

Supposes something contrary to present fact

If I had wings, I would fly.

4. Type 3: untrue in the past

Regret about something that did not happen in the past

If she had called, I would have answered.

Signal words

WordExampleNote
ifIf you study hard, you will pass.The most basic conditional linking word
unlessUnless you hurry, you'll be late.unless = if not, so never put 'not' after it
provided thatI'll go provided that you come too.More formal than 'if'
as long asYou can stay as long as you're quiet.Less formal than 'provided that'
even ifI'll go even if it rains.Stresses that the result holds even if the condition is met

Tips and common mistakes

Conditionals exercises with answers

Fill in the blank, then open the answer to check it.

1. If it ___, I will take an umbrella. (rain)

Options: rained · rains · will rain · would rain

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rains. Type 1: the IF clause takes the present simple, never 'will'.

2. If I ___ you, I would apologize. (be)

Options: am · was · were · would be

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were. Type 2: 'were' is used for every person, as in 'If I were you'.

3. If she ___ harder, she would have passed. (study)

Options: had studied · has studied · studied · would study

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had studied. Type 3: the IF clause takes the past perfect (had + past participle).

4. If you ___ ice in water, it floats. (put)

Options: put · puts · will put · would put

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put. Type 0: both clauses take the present simple, for a general truth.

5. If you ___ your homework, you can go out. (finish)

Options: finish · finished · will finish · would finish

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finish. Type 1: the IF clause takes the present simple.

6. If I ___ a million dollars, I would buy a house. (have)

Options: had · have · will have · would have

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had. Type 2: the IF clause takes the past simple, for something untrue.

7. If I had known, I ___ you. (help)

Options: helped · will help · would have helped · would help

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would have helped. Type 3: the main clause takes 'would have' + past participle.

8. If he ___ (come) to the party, he will have fun.

Options: came · comes · will come · would come

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comes. Type 1: the IF clause takes the present simple, with -s in the third person.

9. If they ___ (not/be) so tired, they would go out. (be)

Options: aren't · hadn't been · weren't · won't be

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weren't. Type 2: the IF clause takes the past simple, and the negative of 'were' is 'weren't'.

10. I would buy it if it ___ cheaper. (be)

Options: has been · is · were · will be

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were. Type 2: the IF clause takes the past, with 'were' for every person.

11. If she ___ the answer, she would tell you. (know)

Options: had known · knew · knows · will know

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knew. Type 2: the IF clause takes the past simple.

12. If I ___ wings, I would fly to you. (have)

Options: had · had had · have · will have

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had. Type 2: a supposition untrue in the present, so the past simple is used.

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