Simple explanation
What is the zero conditional? The zero conditional is a type of conditional sentence. We use it when a condition always or usually leads to the same result. It is common when we talk about general truths, simple scientific facts, rules, habits, instructions, and regular reactions. How do we form the zero conditional? A zero conditional sentence normally has two parts: a condition and a result. The condition often begins with if. In the basic pattern, both parts use the present simple. For example: If I drink coffee at night, I don't sleep well. The first part gives the condition, and the second part gives the usual result. It is not only for scientific facts The zero conditional can also describe personal habits and regular reactions. For example, If I miss the bus, I walk to work describes what the speaker normally does in that situation. The important idea is that the relationship is regular or typical, not a prediction about one specific future event. Changing the order of the clauses The if-clause can come first or second. Compare: If I'm tired, I go to bed early. I go to bed early if I'm tired. The basic meaning stays the same. When the if-clause comes first, we normally put a comma after it. When it comes second, we normally do not use a comma before if. Using if and when In many zero conditional sentences, when can replace if when we mean that something happens every time or regularly. For example: When it rains, the streets get wet. If focuses on the condition, while when can have the meaning of 'whenever' in these situations. Positive, negative, and question forms The verbs in a zero conditional follow the normal present simple rules. This means either clause can be negative with don't or doesn't. We can also ask about the result of a condition, for example: What happens if you press this button? The question itself follows normal present simple grammar.
Grammar formula
Positive form
If + subject + present simple, subject + present simpleIf you heat ice, it melts.
Negative condition
If + subject + don't/doesn't + base verb, subject + present simpleIf I don't eat breakfast, I get hungry early.
Negative result
If + subject + present simple, subject + don't/doesn't + base verbIf she drinks coffee late, she doesn't sleep well.
Result clause first
Result clause + if + condition clausePlants die if they don't get enough water.
Question about a result
What happens + if + subject + present simple?What happens if you press this button?
Core rules
- 1
Use the present simple in both clauses
The basic zero conditional pattern uses the present simple for both the condition and the result: If + present simple, present simple.
- 2
Use it for general or regular results
Choose the zero conditional when a condition always, generally, or normally leads to a particular result.
- 3
Do not normally use will in the basic pattern
The zero conditional is not normally a prediction about one specific future situation. In its basic A2 pattern, use the present simple rather than will in the result clause.
- 4
The two clauses can change position
You can put the if-clause first or second without changing the basic relationship between the condition and the result.
- 5
Use normal present simple negatives
Use don't with I, you, we, and they, and doesn't with he, she, and it. After don't or doesn't, use the base form of the verb.
- 6
Use when for regular situations when appropriate
When can often replace if when the meaning is 'whenever this happens.' This is especially natural for repeated situations and general results.
Useful examples
If you heat ice, it melts.
Heating ice makes it turn into water.
This describes a general result.
If I drink coffee at night, I don't sleep well.
Drinking coffee at night usually makes it difficult for me to sleep well.
This is a regular personal reaction.
If people don't drink enough water, they get thirsty.
People become thirsty when they do not drink enough water.
The condition is negative with don't.
My phone turns off if the battery is empty.
My phone switches off whenever its battery has no power left.
The result clause comes before the if-clause.
If you mix blue and yellow, you get green.
Mixing blue with yellow produces green.
This sentence describes a general result.
If my brother cooks, he usually makes pasta.
My brother normally makes pasta whenever he cooks.
Usually makes the repeated meaning especially clear.
If I miss the bus, I walk to work.
When I miss my bus, my normal solution is to walk to work.
This describes a routine response to a situation.
Plants die if they don't get enough water.
Plants cannot live when they regularly receive too little water.
The negative if-clause comes second.
When it rains, the streets get wet.
The streets become wet whenever it rains.
When works naturally because the relationship is regular.
If you don't charge your phone, the battery runs out.
A phone eventually loses its battery power when you do not charge it.
The condition is negative, but the result is positive.
If she feels tired, she goes to bed early.
Going to bed early is her usual response when she feels tired.
This describes a habit, not one particular future plan.
What happens if you press this button?
What is the usual result of pressing this button?
This question asks about the result of an action.
Common mistakes
- ❌ If you heat ice, it will melt. ✅ If you heat ice, it melts. For this general fact, the basic zero conditional uses the present simple in both clauses.
- ❌ If she drink coffee late, she doesn't sleep well. ✅ If she drinks coffee late, she doesn't sleep well. With he, she, and it, a positive present simple verb normally takes -s or -es.
- ❌ If I don't eat breakfast, I am get hungry. ✅ If I don't eat breakfast, I get hungry. Get is the main verb here, so we do not add am before it.
- ❌ If it rains the streets get wet. ✅ If it rains, the streets get wet. When the if-clause comes first, we normally separate it from the result clause with a comma.
- ❌ Plants dies if they don't get water. ✅ Plants die if they don't get water. Plants is plural, so the present simple verb is die, not dies.
- ❌ If he doesn't sleeps enough, he feels tired. ✅ If he doesn't sleep enough, he feels tired. After doesn't, use the base form of the verb: sleep, not sleeps.
Learning tips
- Ask yourself: Does this result always or usually happen under this condition? If yes, the zero conditional may be appropriate.
- Remember the basic pattern: if + present simple, present simple.
- Do not limit the zero conditional to scientific facts. It is also useful for habits, rules, and regular personal reactions.
- Use a comma when the if-clause comes at the beginning of the sentence.
- Think of when as 'whenever' in many regular zero conditional situations.
- Before using will, check whether you are describing one future possibility or a general, repeated relationship.
Practise this topic
Interactive exercises for this topic are coming soon.
PlannedRelated grammar
Related dictionary words
Frequently asked questions
Is the zero conditional only used for scientific facts?
No. It is also used for rules, habits, instructions, and regular personal reactions. The important point is that the result generally or normally happens when the condition is true.
Why don't we normally use will in the zero conditional?
The zero conditional usually describes a general or repeated relationship, not one specific future event. That is why the basic pattern uses the present simple in the result clause.
Can I use when instead of if?
Yes, in many general or repeated situations. When often has the meaning of 'whenever' and is natural when the result regularly follows the situation.
Do I always need a comma in a zero conditional sentence?
No. Use a comma when the if-clause comes first: If I'm tired, I go to bed early. You normally do not need one when the if-clause comes second: I go to bed early if I'm tired.
What is the difference between the zero conditional and the first conditional?
The zero conditional describes general truths, habits, rules, and regular results. The first conditional usually describes a real or possible future situation and its possible future result.
Can a zero conditional sentence be negative?
Yes. Either clause can be negative. For example: If I don't sleep enough, I feel tired. You can also say: If she drinks coffee late, she doesn't sleep well.