The first conditional talks about a real and possible future situation. The if-clause names the condition, and the main clause names the result: "If it rains tomorrow, we will stay at home." The rain is possible, so the sentence describes a real plan, not a daydream.
The pattern is simple, but one detail surprises every learner: the if-clause takes the present simple, never will. The future marker lives in the main clause. "If it will rain" is wrong in this pattern.
This page explains when to choose the first conditional rather than the zero, second or third, shows the alternatives to will in the result clause, and covers unless. The 20-question drill ends the page, with a rule explanation under each answer.
The rule
The form
- Pattern: if plus present simple, plus will plus the base verb. "If you hurry, we will catch the train."
- The two clauses can change places: "We will catch the train if you hurry." No comma when the main clause comes first.
- Negative: "If you do not hurry, we will miss the train."
- Question: "Will you come if I buy the tickets?"
- The if-clause never takes will in this pattern: "If you hurry", not "If you will hurry".
Real possibilities about the future
- Use the first conditional when the condition is possible and the result is in the future.
- "If the bus is late, I will call you." The bus may be late; the call is the plan.
- The condition can be likely, unlikely or fifty-fifty. The point is that the speaker treats it as real, not imaginary.
- For facts that are always true, use the zero conditional instead: "If you heat ice, it melts."
What can replace will in the result
- Can shows ability or permission: "If you finish early, you can go home."
- May or might shows a possible result: "If she calls, I may not answer."
- Going to shows a plan: "If we save enough, we are going to visit Japan."
- The imperative gives an instruction: "If you see Sam, ask him to call me."
- Should gives advice: "If you feel ill, you should rest."
Unless and if not
- Unless means if not: "Unless you hurry, we will miss the train."
- The unless-clause is positive in form even though the meaning is negative. Never add not after unless.
- You can also say "if... not": "If you do not hurry, we will miss the train."
- Both versions take the present simple in the condition clause.
If or when
- If suggests that the situation may or may not happen: "If I go to Paris, I will visit the Louvre."
- When suggests that the situation will definitely happen: "When I go to Paris, I will visit the Louvre."
- Both use the present simple for a future meaning.
- The comma rule is the same for both: comma after the condition clause, no comma when it comes second.
Examples
- If it rains tomorrow, we will cancel the picnic.A real possibility, so the first conditional is correct.
- If you study hard, you will pass the exam.The condition is possible and the result is in the future.
- She will call you if she gets any news.Main clause first, so no comma before if.
- Unless you hurry, we will miss the train.Unless means if you do not hurry.
- If I have time, I will help you with the report.The if-clause takes the present simple have, not will have.
- If you see Sam, ask him to call me.The main clause is an imperative, so it needs no will.
- If the weather is nice, we can have lunch outside.Can replaces will in the result clause.
- If she finishes early, she may join us.May shows a possible result.
- If you do not water the plant, it will die.A negative if-clause uses do not plus the base verb.
- Will you come to the party if I buy you a ticket?A question with will in the main clause.
Common mistakes
- Wrong: If it will rain tomorrow, we will cancel the picnic. Right: If it rains tomorrow, we will cancel the picnic.
- The if-clause of the first conditional takes the present simple, even about the future.
- Wrong: If you will study hard, you will pass the exam. Right: If you study hard, you will pass the exam.
- Will never goes directly after if in the first conditional.
- Wrong: Unless you do not hurry, we will miss the train. Right: Unless you hurry, we will miss the train.
- Unless already contains the negative meaning. Adding not makes a double negative.
- Wrong: If I will have time, I will help you. Right: If I have time, I will help you.
- The present simple have carries the future meaning in the if-clause.
- Wrong: If you water the plant it will grow. Right: If you water the plant, it will grow.
- A comma separates the if-clause from the main clause when if comes first.
Practice drill
Answer all 20 questions. Each answer is marked at once, and the rule is explained under the question.
If it ___ tomorrow, we will cancel the picnic.
Show answer and explanation
Answer: A. rains The if-clause of the first conditional takes the present simple: if it rains.
If you study hard, you ___ the exam.
Show answer and explanation
Answer: B. will pass The result clause of the first conditional takes will plus the base verb: will pass.
She will call you if she ___ any news.
Show answer and explanation
Answer: C. gets The if-clause stays in the present simple even when the sentence looks forward: if she gets.
Unless you hurry, we ___ the train.
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Answer: D. will miss Unless means if not, and the result clause takes will: we will miss the train.
If I ___ time, I will help you with the report.
Show answer and explanation
Answer: A. have The present simple have carries the future meaning in the if-clause.
If you do not water the plant, it ___ .
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Answer: B. will die The real future result takes will: it will die.
I will go to the party if I ___ work early.
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Answer: C. finish The if-clause takes the present simple: if I finish early.
If you see Sam, ___ him to call me.
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Answer: D. ask The result clause can be an imperative: ask him to call me.
We will stay inside if it ___ cold.
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Answer: A. is A possible future condition takes the present simple: if it is cold.
If she ___ the answer, she will tell us.
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Answer: B. knows The if-clause uses the present simple knows for a real future possibility.
Unless we leave now, we ___ late.
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Answer: C. will be Unless introduces a real condition, and the result uses will: we will be late.
If the bus arrives on time, we ___ the nine o'clock train.
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Answer: D. will catch The future result of a real condition takes will: will catch.
What ___ you do if you lose your phone?
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Answer: A. will The first conditional question uses will in the main clause: What will you do?
If you ___ the instructions, the app will work.
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Answer: B. follow The if-clause takes the present simple: if you follow the instructions.
If you are tired, ___ a break.
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Answer: C. take The result clause can be an imperative: take a break.
Will you come if I ___ you a ticket?
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Answer: D. buy The if-clause stays in the present simple: if I buy you a ticket.
If they ___ late, we will start without them.
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Answer: A. are A real future condition takes the present simple: if they are late.
She will not pass if she ___ harder.
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Answer: B. does not study The negative if-clause uses do or does plus not: if she does not study.
If the weather ___ nice, we will have a picnic.
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Answer: C. is The present simple is carries the future meaning in the if-clause.
If he ___ his homework, he can watch TV.
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Answer: D. finishes The if-clause takes the present simple, and can replaces will in the result: if he finishes.
Questions learners ask
What is the difference between the zero and first conditional?
The zero conditional states a fact or habit that is always true: "If you heat ice, it melts." The first conditional describes a real future possibility: "If it snows tonight, school will close." Both use the present simple in the if-clause. The difference is the result clause: present simple for facts, will for the future.
Can I use "might" instead of "will" in the result?
Yes. Will says the result is confident. Might and may say the result is possible but not certain: "If I finish early, I might go for a run." The condition stays in the present simple in every case.
Does the first conditional use "was" or "were"?
The first conditional uses the ordinary present or past forms of the real situation: "If it rains", "If she is at home". Were belongs to the second conditional, where the situation is imaginary: "If I were rich, I would travel." In the first conditional the condition is possible, so no were is needed.
More grammar topics
Second conditional
If plus the past simple, would plus the base verb: the present that is not real.
Third conditional
If plus had and the past participle, would have plus the past participle: the past that cannot change.
Reported speech
Direct to indirect: one step back, pronouns move, time words change, say vs tell.
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