First conditional

Form

if + subject + present tense, subject + modal + infinitive
If- (or dependent) clause, main clause
(Condition clause, result clause)

subject + modal + infinitive + if + subject + present tense,
main clause + if- (or dependent) clause
(Result clause + condition clause)

Use the first conditional for possible situations in the future

We use the first conditional to talk about future situations that may really happen.

If I see Michaela, I'll tell her to call you.
It is possible I will see Michaela.

If it rains, we'll have to eat indoors.
It is possible that it will rain.

Use present tenses with the first conditional

It is common to use the present simple with the first conditional

The present simple is often used with first conditional sentences.
If I go to the shops, I'll buy some fruit.
You'll catch a cold if you go out without a coat.
However, other tenses can be used. (Real conditionals can include any tenses that are normally used in a situation.)

The present continuous, present perfect and other verb forms in the if-clause

If you've finished in the bathroom, I'm going to have a shower.
The present perfect here shows a past action (finish) with a present result.

If you're meeting Jacqui tonight, you can ask her about her birthday party.
The present continuous here refers to a future arrangement.

If you're going to clean the house, could you do my bedroom first.
Be going to is used here for an intention.

Will in the if-clause for polite requests

Will is not commonly used in the if-clause (see common errors below). However, it can be used for polite requests.
If you'll take a seat, I'll tell her you're here.
(Receptionist talking to a visitor.)

Mixed conditionals

Some conditional sentences do not follow the time relationships shown above. See mixed conditionals for more details.

Use may, might and other modals where necessary

May and might for less certain results

We can use may or might when the result is less certain.

If I have time, I'll go to the supermarket.
If I have time, I may go to the supermarket.
In the first example the result is certain; in the second it is uncertain.

Can, could and should

Other modals can be used to express various functions in the result clause.

If you go into town, could you get me a newspaper. (Could for a request.)
If we have dinner at home, I can watch my favourite TV programme. (Can for ability.)
If you're going to Europe in January, you should take plenty of warm clothes. (Should for advice.)

If and when

When is used with a similar sentence structure, but the meaning is different: if introduces conditions for results that may not happen; when introduces actions with a certain or expected result.

If I see her, I'll tell her
I might see her but I might not - it's only a possibility.

When I see her, I'll tell her
I expect to see her.

Use unless, providing, as long as and on condition that instead of if

Use unless to mean if not in the sense except if

We'll go to the beach unless it rains.
We'll go to the beach if it doesn't rain.

Unless I hear from you, I'll assume you're coming to the meeting.
If I don't hear from you, I'll assume you're coming to the meeting.

Providing (or provided), as (or so) long as, and on condition that

These emphasise that the condition must be met before the result can happen.
I'll lend you my car as long as you promise to drive carefully.
You can go to the party on condition that you're back by midnight.
Provided that the documents are in order, the consignment will be cleared by customs today.

Common errors

A common error is to use will or other modal in the if (condition) clause.*
If I will see Petra, I'll tell her to call you.
In a first conditional sentence, if is usually followed by a subject and a present verb.
* Will can be used in a condition clause in very polite requests.
If you'll sign here, I'll prepare the invoice.
Polite requests such as this can be made even more polite with past modals would or could.