First Conditional: Rules, Examples and Practice
Learn the first conditional in English with clear rules, real-life examples, and practice exercises. Master if + present simple + will structure for B1-B2 learners.
First Conditional: Rules, Examples and Practice
Learn the first conditional in English: how to form it, when to use it, and how to avoid common mistakes. This guide includes clear rules, real-life examples, comparison tables, and practice exercises for B1-B2 learners.
What Is the First Conditional?
The first conditional is a sentence structure used to talk about real and possible situations in the future. It connects a condition that might happen with a likely result.
If + present simple ... + will + base verb
Example 1: If it rains, I will take an umbrella.
Condition: it rains (real possibility) | Result: I take an umbrella (future action)
Example 2: If she studies hard, she will pass the exam.
Condition: she studies (real possibility) | Result: she passes (future outcome)
Example 3: If you leave now, you will catch the bus.
Condition: you leave now (real possibility) | Result: catch the bus (future benefit)
How to Form the First Conditional
The first conditional has two parts, the if-clause (condition) and the result clause (consequence). You can put either clause first, but the meaning stays the same.
| Structure | Example |
|---|---|
| If-clause first | If you study, you will pass. |
| Result clause first | You will pass if you study. |
Important: When the if-clause comes first, use a comma after it. When the result clause comes first, no comma is needed. For example: If you study, you will pass. vs You will pass if you study.
Variations Using Modal Verbs
Instead of will, you can use other modal verbs in the result clause to express different meanings.
| Modal | Meaning | Example |
|---|---|---|
| can | Ability / permission | If you finish early, you can leave. |
| might | Possibility (less certain) | If it snows, we might stay home. |
| should | Recommendation / advice | If she calls, you should answer. |
| must / have to | Necessity / obligation | If you drive, you must wear a seatbelt. |
| may | Formal possibility | If the weather improves, we may go out. |
Using Unless in First Conditional Sentences
Unless means if not. It is a useful alternative that adds variety to your English.
| With Unless | Meaning |
|---|---|
| I will go unless it rains. | I will go if it does not rain. |
| Unless you hurry, we will be late. | If you do not hurry, we will be late. |
| She will not call unless she needs help. | She will only call if she needs help. |
Common mistake: Do not use not after unless. "Unless it does not rain" is wrong. Use "Unless it rains" (meaning: if it does not rain).
First Conditional With When
Sometimes learners use when instead of if. The choice changes the meaning of the sentence.
| Word | Meaning | Example |
|---|---|---|
| if | Possible but not certain | If I get promoted, I will celebrate. (maybe) |
| when | Certain to happen | When I get promoted, I will celebrate. (definitely) |
Using the Imperative in the Result Clause
You can use the imperative form in the result clause to give instructions, advice, or warnings.
- If you feel tired, go to bed early.
- If he calls, tell him I am busy.
- If you see her, say hello from me.
- If the fire alarm rings, leave the building immediately.
Common Mistakes to Avoid
Using will in the if-clause
Incorrect: "If it will rain, I will stay home."
Correct: "If it rains, I will stay home." (present simple in the if-clause)
Forgetting the comma
Incorrect: "If you leave now you will catch the bus."
Correct: "If you leave now, you will catch the bus."
Using unless with a negative verb
Incorrect: "Unless you do not hurry, we will be late."
Correct: "Unless you hurry, we will be late." (unless already means if not)
Using present simple for both clauses
Incorrect: "If it rains, I stay home."
Correct: "If it rains, I will stay home." (use will in the result)
Confusing first and zero conditional
Zero: "If it rains, the ground gets wet." (always true)
First: "If it rains, I will take an umbrella." (future possibility)
First Conditional vs Other Conditionals
Understanding how the first conditional compares to other conditionals helps you choose the right structure.
| Type | Usage | Example |
|---|---|---|
| Zero | General truths | If you heat ice, it melts. |
| First | Real future possibilities | If I study, I will pass. |
| Second | Unreal / imaginary present | If I studied, I would pass. |
| Third | Unreal past / regret | If I had studied, I would have passed. |
Practice Exercises
Exercise 1: Complete the sentence (fill in the verb)
- If it ___ (rain), I will stay home.
- She will be late if she ___ (not hurry).
- If you ___ (eat) too much, you will feel sick.
- They ___ (be) happy if you visit them.
- If he ___ (not study), he will fail the test.
Exercise 2: Choose the correct word (if / unless / when)
- I will call you ___ I arrive. (definitely arriving)
- We will miss the train ___ we leave now.
- ___ you need help, just ask.
- I will not go ___ she invites me.
- ___ the meeting ends, I will let you know. (certain to end)
Exercise 3: Correct the mistake
- If it will rain, I will take an umbrella.
- Unless you do not study, you will fail.
- If she calls I will answer.
- If I have time I will help you.
- If he will come, we will be happy.
Answers
Exercise 1: 1. rains, 2. does not hurry, 3. eat, 4. will be, 5. does not study
Exercise 2: 1. when, 2. unless, 3. If, 4. unless, 5. When
Exercise 3: 1. If it rains... 2. Unless you study... 3. If she calls, I... 4. If I have time, I... 5. If he comes, we...
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