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3.08 "If" structures (conditionals)

"Conditionals" are also referred to as "if clauses", although if is not the only word used in such constructions (see below).

They are also often divided into four "types": “zero”, "first", "second" and "third" conditionals: this can be useful distinction up to a point, but students should realise that there is more flexibility of use than these categories may suggest.

The construction is often used to indicate an uncertain event or situation. Special tenses are usually used to show this uncertainty or "distance from reality".

The four main types of 'if' sentences in English:

1. The 'zero' conditional, where the tense in both parts of the sentence is the simple present:

'IF' CLAUSE If + simple present If you heat ice If it’s hot

MAIN CLAUSE simple present it melts. shops sell more ice cream.

In these sentences, the time is now or always and the situation is real and possible. They are often used to refer to general truths.

2. The Type 1 conditional, where the tense in the 'if’ clause is the simple present, and the tense in the main clause is will/going to/present progressive (referring to the future), a modal verb such as may, might, could or should, or an imperative.

'IF' CLAUSE If + simple present If it rains If you don't hurry If + simple present If you keep speaking French If + simple present If you don’t feel better tomorrow If I get this work finished

MAIN CLAUSE will you will get wet. we will miss the train. going to I’m going to get angry. modal verb you should go and see the doctor. I might go to the pub.

In these sentences, the time in the “if” clause is the present or future (usually future) and in the main clause future, and the situation is real. They refer to a possible condition and its probable result.
Note that the present simple is used to refer to the future here.

3. The Type 2 conditional, where the tense in the 'if' clause is the simple past, and the verb in the main clause is would/could/may/might/should + infinitive:

'IF' CLAUSE If + simple past If you paid more attention If you went to bed earlier If I had more hair

MAIN CLAUSE modal + infinitive you wouldn’t make so many mistakes you might not be so tired. I’d feel younger.

In these sentences, the time is now or the future, and the situation is unreal. They are not based on fact, but refer to an unlikely or hypothetical condition and its probable result.

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4. The Type 3 conditional, where the tense in the 'if' clause is the past perfect, and the tense in the main clause is would/could/may/might/should have + participle:

'IF' CLAUSE If + past perfect If it hadn’t rained If you had worked harder

MAIN CLAUSE Perfect conditional England would have won. you might have passed the exam.

In these sentences, the time is past, and the situation is contrary to reality. The facts are based on are the opposite of what is expressed, and they refer to an unreal past condition and its probable past result.

A further type if 'if' sentence exists, where Type 2 and Type 3 are mixed. The tense in the 'if' clause is the past perfect, and the tense in the main clause is would/could/may/might/should + infinitive

'IF' CLAUSE If + past perfect If I had worked harder at school If we had looked at the map

MAIN CLAUSE Present conditional I would have a better job now. we wouldn't be lost.

In these sentences, the time is past in the 'if' clause, and present in the main clause. They refer to an unreal past condition and its probable result in the present.

In a bit more detail:

Talking about uncertain or imagined situations in the present or future

The choice of tense depends on the degree of possibility of the event, action or situation. This will often be a matter of personal interpretation. Look at the following:

If I get home in time, I'm going to do some gardening.
If the Conservatives win, I'll emigrate.

In both cases, the speaker thinks that there is a fairly good chance of the "condition" happening (getting home and winning), so the present simple is used after if (even though it is referring to the future) and a future tense in the other part of the sentence. May, might or could; should; the present continuous (progressive), or an imperative could also be used in this second part:

Unless you buy another drink, I'm going.
Taxes might rise if a new government is elected.
If you see Basil, give him my regards.

However, if the speaker thinks that the situation is improbable or impossible, different tenses are used:

If I ruled the world, every day would be the first day of spring.
If I were you, I wouldn't bother.
If I retired tomorrow, I might travel around the world.

In the if clause, the simple past tense is used, even though the speaker is referring to the present (If I were you) or the future (If I retired...). This special use of the tense indicates the unreality of the situation.

Talking about unreal or imagined situations in the past

If you want to talk about something that didn't happen in the past, this is how you do it:

If I had seen you, I would have said hello.

(In this case, I didn't see you, so I didn't say hello).

Notice that in standard English, there is no would in the if clause. (People around Birmingham, though, tend to say "If I'd've seen you ... "). Here are some more examples of the past conditional: note carefully the verb forms used:

If I'd woken up earlier, I wouldn't have missed the bus.
If I hadn't been working there, I wouldn't have met her.
We would have been able to finish the testing if we had had more time.

Note also that the part of the sentence after the if clause is often in the present:

If I hadn't eaten that Balti last night, I wouldn't be ill now.

Other notes on using conditionals

If is not the only word used in this type of sentence. Note these examples:

Providing/provided you work hard, you should be able to pass.
You can borrow my car as/so long as you're very careful with it.
Supposing you lost your job, what do you think you would do?
You can have an extension on condition that you don't ask for any more.
Imagine you won the competition. What would you do?

In formal English, if is sometimes omitted and the auxiliary verbs were, had and should placed before the subject:

Had I known earlier, I wouldn't have allowed it.
Should you decide not to take the matter further, please inform us.
Were it not for you invaluable assistance, the project would not be possible.

Will and would are not usually found in the if clause. There are used, however, in polite requests, such as:

If you will just wait a moment, the doctor will see you when she's free.

Would is fairly commonly used after if when making polite/formal requests in letters:

I would be most grateful if you would consider my application at your earliest convenience.

Links to further resources on "if" structures UsingEnglish.com BBC Edufind

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Steve Gould
Last updated: 27 May 2011