The Conditional in English Grammar

In English, the ‘conditional’ is a grammatical construction that is used to express sentences that are based on a condition, which can be real or unreal, as well as based in the past, present or future. Conditional sentences are called ‘conditionals’ because the possibilities they talk about, whether real or unreal possibilities, are dependent on a condition.

There are four main types of conditionals in English, and they are called ‘zero’, ‘first’, ‘second’ and ‘third’. Zero and first conditionals are ‘real’ conditionals in that they express real possibilities. Second and third conditionals are ‘unreal’ conditionals because they express hypothetical possibilities.

In addition to these four clearly structured conditionals (unhelpfully numbered zero to three) there is a further category called ‘mixed’ conditionals, in which the zero, first, second and third conditionals are mixed.

But, you may be asking, what does a conditional sentence look like?

• If I give you an example of a conditional sentence, you will know how one looks.

That is an example of a conditional sentence.

Conditional sentences consist of two parts, called ‘clauses’.

A clause is a group of words that contains a subject and a verb, and forms a sentence or part of a sentence. For more information on clauses, please see the relevant article.

What we express in the main clause (the conditional clause) depends on (or is conditional on) what we express in the subordinate clause (the if clause). Here are some examples,

• I’ll help you if you want.
• If you want, I’ll help you.
• He’d come if you called him
• If you called him, he’d come.
• I’ll turn on the heating if it gets colder.

An important thing to bear in mind, as you look through the various examples of conditional sentences above, is that the ‘if clause’ can come first or last; both are acceptable and have the same meaning. The only difference is that if you put the ‘if’ clause first, you will need to use an adverbial comma. For more on comma usage, please see the relevant post.

Conditional sentences can be questions as well as statements:

• If it starts to rain, may I use your umbrella?

Conditional sentences can be positive or negative:

• If you had called him, he would have come.
• If you hadn’t called him, he wouldn’t have come.

Zero conditional

Zero conditional is the basic conditional form; it is a real conditional that expresses general truths.

The structure of a zero conditional:

If + present tense (if clause/subordinate clause)             Present tense (conditional clause/main clause)

Zero conditional uses the simple present tense, which is the tense used to express general truths in English grammar. Please refer to the following post for more on the English tenses.

• If you press the button, it makes a noise.
• If you want to change money on a Sunday, you have to go to one of the big railway stations.
• Most cats purr if you tickle them under the chin.

First conditional

Sometimes called the ‘type 1 conditional’, the first conditional is a real conditional and it refers to something that is effectively in the future.

The structure of a first conditional:

If + present tense (if clause/subordinate clause)      Will/going to or similar future form (conditional clause/main clause)

• He’s going to get here early if he catches the fast train.
• If it rains tomorrow, I am bringing my umbrella to work. (present continuous used in a future sense)
• If you study hard for the exam, you will earn a good mark.
• If she calls me back, I’ll be able to answer her questions about the project.

Second conditional

Also called the ‘type 2 conditional’, the second conditional is sometimes referred to as an ‘unreal conditional’ because it is specifically related to hypothetical conditions. The second conditional refers to a hypothetical condition related to the present or the future.

The structure of a second conditional:

If + past tense (if clause/subordinate clause)    Would/Should/Might/etc + bare infinitive (conditional clause/main clause)

• If he didn’t annoy me so much, I’d spend more time in his office.
• If I received an invitation, I would go there right away.
• I might buy a car if I win the lottery.

A confusing detail for some concerning the hypothetical, type 2 conditional is that the subordinate clause changes to use the past tense. This is because the past tense is also a grammatical structure for expressing hypotheticals in the English language. Events or conditions that are contrary to reality or unlikely to happen can be identified in our speech or writing by the use of the past tense in the subordinate conditional clause.

The second conditional usually uses the word ‘would’ in the main or conditional clause, but it can work with some other words as well:

• I shouldn’t get to sleep at all if I lived next to that noise.
• I might not get to sleep at all if I lived next to that noise.
• If you took a day off, we could go to the park.
• If the river rose, we could run to the mountains.
• If you had a few free minutes, I’d really appreciate a chance to chat.

Third conditional

Also called a ‘type 3 conditional’, the third conditional is sometimes referred to as the ‘past conditional’ because it is the one that is used to speculate hypothetically on past events.

The structure of a third conditional:

If + past perfect tense (if clause/subordinate clause)     Would + have + past participle (conditional clause/main clause)

• I we hadn’t wasted time, we wouldn’t have missed the train.
• I would have been more sympathetic if she hadn’t accused me of lying.
• If you had been to the supermarket, you could have bought some milk.
• If you hadn’t driven so fast, you would never have had the accident.
• If there hadn’t been an accident on the motorway, I would have been there on time.
• Had I known he was ill I’d never have shouted at him.

An overview

Here is an overview of the zero, first, second and third conditionals using similar examples.

• type 0: If you press the button, it makes a noise.
• type 1: If you press the button, it will make a noise.
• type 2: If you pressed the button, it would make a noise.
• type 3: If you had pressed the button, it would have made a noise.

• type 0: If you eat healthily, you feel better.
• type 1: If you eat healthily, you will feel better.
• type 2: If you ate healthily, you would feel better.
• type 3: If you had eaten healthily, you would have felt better.

• type 0: If we talk to people, we cheer them up.
• type 1: If we talk to these people, we will cheer them up.
• type 2: If we talked to these people, we would cheer them up.
• type 3: If we had talked to these people, we would have cheered them up.

Mixed conditionals

As their name suggests, mixed conditionals can be formed by mixing elements of different conditional forms. For example, combining elements of the first and third conditionals, or the second and third conditionals.

While it is most common to mix the second and third conditionals, or the first and third conditionals, one can potentially mix elements from any conditional forms to convey more nuanced meanings or complex hypothetical situations as they arise.

Second and Third Conditionals Mix:

• If you had studied harder, you wouldn’t be struggling now.

Combines the past unreal condition from the third conditional in the subordinate clause with the present unreal result from the second conditional in the main clause.

Conditional sentences with words other than ‘if’

Most commonly, an ‘if’ is associated with the subordinate clause of a conditional sentence, but a similar word can also be used in a conditional sense:

• Had I been there, I could have saved him.
• Were I there, I would have helped him.
• Should you see him, please ask him to give me a call.

The word ‘unless’ is used to express a negative condition or exception:

• Unless you hurry, you will miss the bus.
• If you hurry, you will not miss the bus.

Note the difference in meaning here with the word ‘if’.

Conclusion

In reality, zero and first conditionals are used regularly without a speaker having to think about their construction. For learners of English, the second and in particular the third require some practice. When one looks at the overview of the conditionals and sees how one gradually becomes another, it is far easier to think of examples and conditional situations in which one might need to use the different types. The zero type states a general fact; the first states a definite outcome, the second states a hypothetical outcome and the third reflects on the past, had it been different.

Try to create some basic zero conditionals for yourself, and then go through the stages of changing them to a first, second and third.

If you have any comments or queries, please do enter them below.

Exercises to practise

The following sentences have all been written in the first conditional. Have a go at converting them to the conditional type written beside them in brackets.

1. If it rains tomorrow, I will stay indoors (2)
2. What will you do if you miss the bus? (3)
3. She’ll be happy if she receives the job offer. (3)
4. Will you come to the party if you’re free? (2)
5. If I have enough time, I’ll help you with your project. (3)
6. What time will you leave if the meeting ends early? (3)
7. If he studies hard, he’ll pass the exam. (2)
8. If we hurry, we can catch the train. (3)
9. Will you call me if you need any assistance? (2)
10. If you eat too much, you’ll feel sick. (0)
11. If they find their keys, they won’t be locked out. (3)
12. What will happen if they arrive late to the airport? (2)
13. If she saves enough money, she’ll go on holiday. (2)
14. If you don’t water the plants, they will die. (0)
15. What will you say if they ask you about your future plans? (2)
16. If the restaurant is crowded, we may have to wait for a table. (3)
17. If he arrives on time, the presentation will start promptly. (2)
18. Will you be upset if the concert is cancelled? (2)
19. If you exercise regularly, you’ll become healthier. (0)
20. If it snows tonight, the roads will be slippery tomorrow morning. (2)

The answers are at the bottom of this page, below the bibliography.

BIBLIOGRAPHY

Burton-Roberts, Noel. Analysing Sentences: An Introduction to English Syntax, 4th edn (Routledge, 2016)

Crystal, David. The Cambridge Encyclopedia of the English Language, 3rd edn (Cambridge University Press, 2019)

Hewings, Martin, and others. Cambridge English Grammar and Vocabulary for Advanced (Cambridge University Press, 2015)

Huddleston, Rodney, and others. The Cambridge Grammar of the English Language (Cambridge University Press, 2002)

Parrott, Martin. Grammar for English Language Teachers, 2nd edn (Cambridge University Press, 2011)

Quirk, Randolph, and others. A Comprehensive Grammar of the English Language, reprint edn (Pearson, 2011)

Seely, John. Oxford A – Z of Grammar & Punctuation (Oxford University Press, 2020)

Yule, George. The Study of Language, 4th edn (Cambridge University Press, 2010)

https://dictionary.cambridge.org/dictionary/english/

https://www.oxfordlearnersdictionaries.com/

Answers to the exercises

1. If it rained tomorrow, I would stay indoors (2)
2. What would you have done if you had missed the bus? (3)
3. She would have been happy if she had received the job offer. (3)
4. Would you come to the party if you were free? (2)
5. If I had had enough time, I would have helped you with your project. (3)
6. What time would you have left if the meeting had ended early? (3)
7. If he studied hard, he would pass the exam. (2)
8. If we had hurried, we could have caught the train. (3)
9. Would you call me if you needed any assistance? (2)
10. If you eat too much, you feel sick. (0)
11. If they had found their keys, they wouldn’t have been locked out. (3)
12. What would happen if they arrived late to the airport? (2)
13. If she saved enough money, she would go on holiday. (2)
14. If you don’t water the plants, they die. (0)
15. What would you say if they asked you about your future plans? (2)
16. If the restaurant had been crowded, we may have had to wait for a table. (3)
17. If he arrived on time, the presentation would start promptly. (2)
18. Would you be upset if the concert were cancelled? (2) (see subjunctive for queries)
19. If you exercise regularly, you become healthier. (0)
20. If it snowed tonight, the roads would be slippery tomorrow morning. (2)