Conditionals are used to describe the result of a real or hypothetical condition. They contain two clauses:
- A clause beginning with ‘If’ that introduces the condition.
- A main clause that indicates the consequence or result of that condition.
There are four main types of conditional in English. Each is used to indicate the likelihood of a situation occurring, or the likelihood that it would have occurred under particular circumstances. The Zero and First conditionals are sometimes known as ‘real conditionals’, because they are used for situations that are certain or highly likely. The Second and Third conditionals are often called ‘unreal conditionals’ because they are used for situations which are improbable or impossible.
The four conditionals.
Zero Conditional (real)
For general and scientific truths (situations in which one occurrence always leads to a particular consequence).
If you heat wax, it melts.
If + present simple tense + present simple tense.
Likelihood = 100%
In sentences using the Zero Conditional, the word ‘If’ can be swapped for the word ‘When’, because the consequence will always be the same: ‘When you heat wax, it melts’.
First Conditional (real)
For real or highly likely future scenarios.
If I get 80% for the exam, I will have an A grade average overall.
If + present simple tense + will + infinitive (without ‘to’)
*Likelihood = > 90%
Second Conditional (real)
For impossible or improbable situations in the present and future.
If I had a photographic memory, I would never need to take notes from books.
If + past simple tense + would + infinitive (without ‘to’)
*Likelihood = < 2%
When ‘If I’ is followed by the verb to ‘be’, it is grammatically correct to say ‘If I were..’, and ‘If he/she/it were’. This use of ‘were’ is a relic of the English subjunctive. However, native speakers will often use ‘was’, particular with he/she/it.
Third Conditional (unreal)
For hypothetical situations in the past (situations that did not occur/unreal imaginary situations). The Third conditional is used to indicate that present circumstances might have been different, had circumstances in the past differed.
If I had been good at maths, I could have been an astrophysicist.
If + past perfect tense + would have + past participle.
*Likelihood = 0%
*These percentages are estimates for illustrative purposes only.
Mixed conditionals are ‘mixed’ in the sense that the condition and the consequence are situated in different periods of time. In other words, the two parts of the sentence refer to different times. Mixed conditionals are commonly used by native speakers, and they always express unreal or impossible situations.
Present condition → Past consequence
If I were a keen writer, I would have become a journalist after leaving university.
But I am not a keen writer, and so I didn’t become a journalist after leaving university.
Present condition → Future consequence
If I were good at public speaking, I would be giving a paper at the conference in New York next month.
But I am not good at public speaking, and so I will not be giving a paper at the conference in New York next month.
Past condition → Present consequence
If I had learnt Spanish at school, I would be able to understand this journal article.
But I didn’t learn Spanish at school, and so I can’t understand this journal article.
Past condition → Future consequence
If I had saved hard enough, I would be going to Ecuador with you next summer.
But I didn’t save hard enough, and so I will not be going to Ecuador.
Future condition → Present consequence
If I were sitting the exam tomorrow, I would be really nervous.
But I will not be sitting the exam tomorrow, so I am not nervous.
Future condition → Past consequence
If I weren’t going to do a PhD at Massey, I would already have applied for a job overseas.
But I am going to do a PhD at Massey, so I didn’t apply for a job overseas.
Punctuation of conditional sentences
Add a comma after the ‘If’ clause, if it precedes the clause describing the consequence.
If I finish a draft of my assignment in time, I will submit it to the pre-reading service.
If the clause describing the consequence precedes the ‘If’ clause, no comma is required.
I will submit a draft of my assignment to the pre-reading service if I finish it in time.
For further information and examples, see:
British Council (n.d.a). Conditionals 1.
British Council. (n.d.b). Conditionals 2.
Grammarly. (n.d.). Conditional sentences.