Zero and First Conditional

Zero and First Conditional

Conditional sentences talk about 'if' situations and their results. The Zero Conditional talks about general facts, rules and things that usually happen. The First Conditional talks about real, possible situations in the future.

Structure

• Zero Conditional: If + present simple, + present simple. Example: If you heat ice, it melts.
• First Conditional (basic form): If + present simple, + will + base verb. Example: If it rains, I will stay home.
• Negative: Use don't or doesn't in the if-part, or won't in the result. Example: If it doesn't rain, we will go out.
• Question: The result part has question word order. The if-part does not change. Example: What will you do if it rains?

How the Grammar Works

1. Use the Zero Conditional for general facts, rules and things that usually happen: If you mix red and blue, you get purple.
2. Use the First Conditional for a specific, realistic future situation: If I finish early, I will call you.
3. In these patterns, use the present simple in the if-part, even when the meaning is about the future. Do not use will there to show future time: If it rains, I will stay home.
4. The two parts can change order. If 'if' comes second, you do not need a comma: I will stay home if it rains.
5. In the Zero Conditional, you can use when instead of if: When you heat ice, it melts. For a specific future situation, if and when are different. If means maybe, and when means you know it will happen: If I see Tom, I will tell him. (Maybe I will see him.) When I see Tom, I will tell him. (I know I will see him.)
6. In the First Conditional, the result can also be an order or can + verb: If you need help, call me. If you finish early, you can go home.

Common Use Cases

• Explaining facts and natural results: If you don't water plants, they die.
• Talking about habits and routines: If I'm tired, I go to bed early.
• Making real future plans: If we hurry, we'll catch the train.
• Warning about results: If you touch that, you'll get hurt.

Frequent Mistakes and How to Avoid Them

• Using 'will' in the if-part. Incorrect: If it will rain, I will stay home. Correct: If it rains, I will stay home.
• Forgetting the comma when 'if' starts the sentence. Incorrect: If it rains I will stay home. Correct: If it rains, I will stay home.

Comparison with Related Grammar

The Zero Conditional is for general facts, rules and things that usually happen. Both parts use the present simple. The First Conditional is for a specific possibility in the future (if + present simple, will + verb).

If you heat ice, it melts. states a general fact. If you heat ice, it will melt. is also correct, but it says what will happen as a result. For a general fact, the present simple is the more natural choice.

Example Sentences

• If you freeze water, it turns into ice. (zero)
• Plants die if they don't get sunlight. (zero)
• If I see him, I will tell him. (first)
• If you study hard, you will pass the exam. (first)
• If it doesn't rain, we will go to the park. (first, negative)
• What will you do if she calls? (first, question)
• If you finish early, you can go home. (first, with can)

When to Use This Rule

Use the Zero Conditional for general facts and things that usually happen. Use the First Conditional for real, possible future situations. In these basic patterns, use the present simple after 'if', not will.