First conditional

Some things might really happen: you might miss the bus, the weather might turn bad, or your boss might call. English uses the first conditional to talk about these real, possible future situations and their likely consequences.

Quick form: If + present simple, will + base verb → If it rains, we will stay indoors. We will stay indoors if it rains.

What the first conditional expresses

The first conditional describes a real or likely possibility and its probable result. The speaker considers the condition genuinely possible:

• Predictions: If you study hard, you'll pass the exam.
• Warnings: If you touch that wire, you'll get a shock.
• Offers and promises: If you help me, I'll buy you lunch.
• Plans that depend on conditions: If the weather is good, we'll have the picnic outside.

The key idea is that the speaker believes the condition could actually happen.

Forming the first conditional

The if-clause uses a present form — usually the present simple — even though it refers to the future. The result clause uses will + base verb:

• If she arrives early, we will start without waiting.
• I will call you if the train is delayed.

Note the comma: when the if-clause comes first, use a comma after it. When the if-clause comes second, you usually do not need a comma.

Will or won't in the result clause

To make the result negative, use won't (will not):

• If you don't hurry, we won't make it on time.
• If you keep ignoring it, the problem won't go away.

You can also make the if-clause negative with standard present-tense negatives — don't/doesn't, isn't/aren't, can't, etc.:

• If he doesn't reply by Monday, send a reminder.
• If they're not careful, they'll miss their flight.

Both clauses can be negative:

• If you don't ask, you won't know.

Other modals in the result clause

Will is the most common modal in the result clause, but others are possible to soften the prediction or show uncertainty:

Using might makes the result sound less certain than will. This is useful when you're not fully confident about the outcome.

Imperative in the result clause

The result clause can also be an imperative (a command or instruction):

• If you feel unwell, stay home.
• If there's a problem, call me immediately.
• Wear a coat if it's cold.

This pattern is natural for advice, instructions, and urgent recommendations.

First conditional vs. zero conditional

Both use an if-clause in the present simple, but they carry different meanings:

The zero conditional presents a result that is always true — a rule of nature or habit. The first conditional presents a result that will (or might) happen in this specific future situation.

No future will in the if-clause

This is the most common mistake with the first conditional. In the standard first conditional, the if-clause uses a present form — not future will:

❌ If it will rain, we will stay indoors. → ✅ If it rains, we will stay indoors.

❌ If you will study harder, you will pass. → ✅ If you study harder, you will pass.

Think of it this way: the if-clause describes the condition; will belongs in the result clause, which describes what will happen because of that condition.

There is one exception: will/won't in an if-clause can express willingness or refusal: If you will wait a moment, I'll get the manager. / If he won't apologise, we'll leave. This is quite formal and uncommon; it does not mean the same thing as a standard first conditional.

Questions in the first conditional

You can form first-conditional questions by inverting the result clause:

• If it rains, will you still come?
• Will you be upset if I'm a bit late?

The if-clause itself stays in the present simple — the question inversion goes in the result clause only.

Common mistakes

• ❌ If she will call, I will answer. → ✅ If she calls, I will answer. (no future will in the if-clause)
• If it is going to rain, we'll cancel is grammatical (especially when using evidence or a forecast), but If it rains, we'll cancel is the simpler, standard form.
• ❌ If I pass the exam, I celebrate. → ✅ If I pass the exam, I will celebrate. (without will, the sentence can sound like a general habit rather than a specific future result)
• ❌ If you would study, you would pass. → ✅ If you study, you will pass. (would … would belongs to the second conditional for imaginary situations — not for real future possibilities)

Quick check

Choose the correct form or rewrite the sentence:

1. If she ____ (study / studies / will study) tonight, she'll do well tomorrow.
2. If you leave now, you ____ (catch / will catch / would catch) the 6 o'clock train.
3. If it rains, we ____ (might cancel / might will cancel) the picnic.
4. Rewrite correctly: If you will call me, I will answer.
5. Which is zero conditional and which is first conditional? a. If you mix red and blue, you get purple. b. If you mix those two chemicals, there will be an explosion.

Key takeaways

• The first conditional uses if + present simple in the condition clause and will + base verb in the result clause.
• Use it for real, possible future situations — the speaker thinks the condition could actually happen.
• In the standard first conditional, don't use future will in the if-clause — use a present form, usually the present simple. Will/won't in an if-clause is reserved for expressing willingness or refusal.
• Might, can, and should can replace will in the result clause to express uncertainty, ability, or expectation.
• An imperative in the result clause is natural for advice and instructions: If you're late, call me.
• Word order is flexible: if the if-clause comes first, add a comma; if it comes second, no comma.
• The first conditional differs from the zero conditional (general rules) and the second conditional (imaginary/unlikely situations).