Zero Conditional: Rules, Examples and Practice
Learn the zero conditional in English with clear rules, real-life examples, and practice exercises. Master if + present simple for general truths and habits.
Zero Conditional: Rules, Examples and Practice
Master the zero conditional in English: when to use it, how to form it, and how it differs from other conditionals. Includes real-life examples, common mistakes, and practice exercises for A2-B1 learners.
The Formula
If / When + present simple, present simple
This structure describes things that are always true, scientific facts, and personal habits.
What Is the Zero Conditional?
The zero conditional is used to talk about things that are always true. Use it for scientific facts, natural laws, general truths, and personal habits. The result is certain - it always happens when the condition is met.
Example: "If you heat ice, it melts."
This is always true. Every time you heat ice, it melts. There are no exceptions.
Three Main Uses
Scientific Facts
Things proven by science. "If you freeze water, it expands."
(Always true, no exceptions.)
General Truths
Things everyone knows. "If you study, you learn."
(Generally true for most people.)
Personal Habits
Your own routines. "If I drink coffee late, I cannot sleep."
(True for you personally.)
Structure Table
The order of the two clauses can be reversed. When the if-clause comes first, use a comma. When the main clause comes first, no comma is needed.
| Structure | Example |
|---|---|
| If + present simple, present simple | If you heat ice, it melts. |
| Present simple + if + present simple | Ice melts if you heat it. |
| When + present simple, present simple | When you heat ice, it melts. |
| Imperative result | If the alarm rings, leave the building. |
If vs When in Zero Conditional
In zero conditional sentences, if and when are almost interchangeable because the result is always certain. However, there is a small difference in emphasis.
Using "If"
Focus on the condition. "If you touch fire, you get burned."
(The condition causes the result.)
Using "When"
Focus on the timing. "When you touch fire, you get burned."
(Whenever this happens, this follows.)
Real-Life Examples by Category
Science and Nature
"If you mix oxygen and hydrogen, you get water."
"If plants do not get sunlight, they die."
"If you drop an object, it falls to the ground."
These are universal laws that never change.
Daily Life and Habits
"If I wake up late, I skip breakfast."
"If my phone battery is low, I charge it."
"If it is sunny, I walk to work."
Personal routines that repeat regularly.
Instructions and Rules
"If the light is red, stop."
"If a customer asks for help, call the manager."
"If you finish the test early, check your answers."
These use the imperative form in the result clause.
Language Learning
"If you practise every day, your English improves."
"If you read English books, your vocabulary grows."
"If you speak with native speakers, you learn faster."
Encouraging truths for English learners.
Zero vs First Conditional
Learners often confuse zero and first conditional. The key difference is certainty. Zero conditional = always true. First conditional = possible future result.
| Aspect | Zero Conditional | First Conditional |
|---|---|---|
| Meaning | Always true / general fact | Possible future situation |
| If-clause tense | Present simple | Present simple |
| Main clause tense | Present simple | Will + base verb |
| Can use "when"? | Yes, same meaning | No, changes meaning |
| Example | If you heat ice, it melts. | If it rains tomorrow, I will stay home. |
Negative Forms
You can make either or both clauses negative using standard present simple negation (do/does not).
Negative if-clause
"If you do not water plants, they die."
Negative main clause
"If I drink coffee late, I do not sleep well."
Both clauses negative
"If you do not practise, you do not improve."
Common Mistakes
Mistake 1: Using "will" in the result clause
Incorrect: If you heat ice, it will melt.
Correct: If you heat ice, it melts.
The zero conditional uses present simple, not future. Use "will" only for first conditional (possible future situations).
Mistake 2: Confusing zero with first conditional
Incorrect: If I drink coffee late, I will not sleep well. (if this is a general habit)
Correct: If I drink coffee late, I do not sleep well.
Use zero conditional for habits (always true) and first for specific future situations.
Mistake 3: Using third person "s" incorrectly
Incorrect: If she study hard, she learn quickly.
Correct: If she studies hard, she learns quickly.
Mistake 4: Forgetting the comma
Incorrect: If you touch fire you get burned.
Correct: If you touch fire, you get burned.
When the if-clause comes first, always use a comma after it.
Mistake 5: Using "if" with imperative incorrectly
Incorrect: If the alarm will ring, leave quickly.
Correct: If the alarm rings, leave quickly.
Practice Exercises
Exercise 1: Complete the sentence (5 questions)
- If you ___ (heat) water to 100 degrees, it boils.
- If I ___ (be) tired, I go to bed early.
- Plants die if they ___ (not get) enough water.
- If she ___ (eat) too much sugar, she feels sick.
- My dog ___ (bark) if someone knocks on the door.
Exercise 2: Choose the correct option (5 questions)
- If you ___ (mix / will mix) blue and yellow, you get green.
- If he ___ (does not sleep / will not sleep) enough, he is grumpy.
- The snow ___ (melts / will melt) if the temperature rises above zero.
- If I ___ (am late / will be late), my boss gets angry.
- If you ___ (touch / will touch) a hot surface, you burn yourself.
Exercise 3: Rewrite using "when" (5 questions)
- If you press this button, the machine starts. → ___
- If the baby cries, I feed her. → ___
- If it rains, the ground gets wet. → ___
- If my internet connection is slow, I restart the router. → ___
- If the teacher gives homework, the students complain. → ___
Practise Conditionals with a Tutor
The best way to master conditionals is to use them in real conversations with a native speaker.
Frequently Asked Questions
What is the zero conditional in English?
The zero conditional describes general truths, scientific facts, and habits. It uses present simple in both clauses. Example: "If you heat ice, it melts."
What is the difference between zero and first conditional?
The zero conditional is for things that are always true (If you heat ice, it melts). The first conditional is for possible future situations (If it rains tomorrow, I will stay home).
Can I use "when" instead of "if" in zero conditional?
Yes. In zero conditional sentences, "when" and "if" are interchangeable because the result is always certain. "When you heat ice, it melts" has the same meaning.
Can the zero conditional use the imperative?
Yes. For instructions and rules, the result clause can use the imperative form: "If the light turns red, stop." This is called the imperative conditional.
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