Conditional sentences in English are used to talk about events and their results.

The zero (0) conditional is the factual conditional. It is used to talk about habits, scientific facts, general truths, instructions and rules, if something else happens first.

If this event happens or if this condition exists, this is what happens.

These are things that are real, so this conditional is also called the real factual conditional or the real present conditional.

A quick review: There are two parts to a conditional sentence. There is an if-clause (also called the conditional-clause) and a main-clause or result-clause. The if-clause contains the condition (the event or situation that must happen first), and the main-clause, which is the result. The two events are connected. One event or situation is a condition for another event or situation.

Learn more: What are conditional sentences?

 

The Zero Conditional Structure

Take a look at this condition:

If I get lost,

This is not a complete sentence. There is some information missing. What happens if you get lost? What do you do? We need another clause to explain what happens.

Take a look at this result:

I ask for directions.

This is a complete sentence, but there is also some information missing. When do you ask for directions? Under what conditions do you ask for directions?

If I get lost, I ask for directions.

This is the easiest conditional sentence remember, because you use the present simple tense in both clauses of the sentence:

If + present simple, present simple

Now that you understand how to form the zero conditional, let’s focus on when to use it.

 

1. Habits

In English, use the present simple tense to talk about habits and daily routines:

I walk the dog every day.
I call my mother once a week.
I babysit my grandchildren every week.

You can also use the zero conditional sentence structure to talk about your habits, or things that you always do in certain situations or conditions.

Finish these sentences with what you do in these situations:

If I get sick, I …
If I miss the train, I …
If I don’t sleep well, I …
If I drink, I …
If it’s hot, I …
If it snows, I …

Remember: You are thinking about your habits, not a specific situation that is happening today or that will possibly happen tomorrow.

Now, take a look at these sentences. Do you do these things? When do you do these things?

I stay home from work.
I drive to work.
I am cranky in the morning.
I never drive.
I go to the beach.
I shovel the driveway.

These things are connected. Let’s put them together in the zero conditional sentence structure.

If this event or condition happens, this is what I do.

If I get sick, I stay home from work.
If I miss the train, I drive to work.
If I don’t sleep well, I am cranky in the morning.
If I drink, I never drive.
If it’s hot, I go to the beach.
If it snows, I shovel the driveway.

What is the difference between talking about habits with the zero conditional and the first conditional?

Here is the easy way to remember the difference:

zero = habits, facts, truths,
first = things that are possible or might happen in the future

Compare these two sentences:

If it’s hot, I go to the beach. (zero)

If it’s hot, I’ll go to the beach. (first)

There is an important difference in meaning between these two sentences. In the first sentence, you are talking about your general habits, not a specific situation. In the second sentence, you are talking about a specific situation, or something that is possible in the future.

Zero conditional:

What do you like to do on weekends?
If it’s hot, I usually go to the beach.
If it’s cold, I stay home and watch Netflix.
(I am talking about my general habits.)

First conditional:

What are you doing this weekend?
If it’s hot, I’ll go to the beach.
If it’s cold, I’ll stay home and watch Netflix.
(I am talking about something that will possibly happen this weekend.)

Learn more: The first 1st conditional sentence

 

 

2. Scientific facts

Here are some scientific facts:

Ice melts.
Oil floats.
Water boils.

These are all complete sentences, but you still feel like you need more information. When does ice melt, oil float, and water boil? Under what conditions?

if you heat it
if you put it in water
if you heat it

These are not complete sentences. What will happen if you heat it?

This is what happens if this happens first.

Ice melts if you heat it.
Oil floats if you put it in water.
Water boils if you heat it.

 

3. General truths & facts

These things are not scientific facts, but they are things that are true, or that we generally believe are true.

If the banana is yellow, it is ready to eat!

It’s bad luck if the groom sees the bride before the wedding!

If the police catch you driving too fast, you get a speeding ticket.

If you make more money, you pay more income tax.

 

4. Instructions & Rules

You can use the imperative in the result-clause to give instructions, advice, or explain rules.

If you want to lose weight, eat less and exercise more.

If you drink, don’t drive.

Please don’t disturb me if I am asleep!

Eat something if you’re hungry.

Call me if you feel sad.

If you don’t like your job, quit!

If you want to speak to someone, press 1.

What is the difference between using the imperative in the zero conditional and the first conditional?

The sentences look exactly the same. The difference is the context. You use the zero conditional to talk about present habits, general truths, and scientific facts. You use the first conditional to talk about things that are possible or may happen in the future.

First conditional sentences with the imperative:

If you call your mother tonight, tell her I said “hello”!

Remember to buy some bananas if you go to the supermarket.

If anyone calls for me, tell them I’m not home!

Learn more: The first 1st conditional sentence

 

NOTES:

a. You can change the order of the clauses.

If this event or condition happens, this is what I do.

This is what I do if this event or condition happens.

I ask for directions if I get lost.
I stay home from work if I get sick.
I drive to work if I miss the train.
I am cranky in the morning if I don’t sleep well.
I never drive if I drink.
I go to the beach if it’s hot.
I shovel the driveway if it snows.

Did you notice that there is no comma between the clauses when they are in this order?

comma: If this event or condition happens, this is what I do.

no comma: This is what I do if this event or condition happens.

 

b. You can use when instead of if.

In the real factual conditional, when and if have a similar meaning.

When I get lost, I ask for directions.

I stay home from work when I get sick.

When I’m in my car, I listen to the radio.

Whenever I cook fish, the house smells.

I smoke when I drink.

When I go to the movies, I eat a bag of popcorn.

I listen to my ipod when I jog.

You can also use the conjunction whenever instead of when or if. Whenever means at any time or every time that (something happens).

 

c. You can use adverbs of frequency.

You can use adverbs of frequency to talk about your habits. An adverb of frequency describe how often you do something.

If I get lost, I always ask for directions.

I usually go to the beach if it’s hot.

I never drive if I drink.

Learn more: English: Adverbs of frequency

 

d. You can use questions in the main-clause.

Use the regular question word order. The question is never in the if-clause.

Do you always ask for directions if you get lost?

If you get sick, do you stay home from work?

Are you cranky in the morning if you don’t sleep well?

You can also use when and whenever instead of if in zero conditional question forms.

Do you always ask for directions when you get lost?

 

 

e. You can make one or both clauses negative.

You don’t have to eat if you’re not hungry.

I don’t ask for directions if I get lost.

If you don’t like my opinion, don’t ask me for it!

If you don’t like peanut butter and chocolate together, you’re not alone!

You can use unless instead of if not in the if-clause:

I can’t drive unless I have my glasses.
(I can’t drive if I don’t have my glasses.)

You can’t drive a car unless you have a license.
(You can’t drive a car if you don’t have a license.)

 

f. You can use modal verbs.

A modal verb is a helping verb. It can’t be used by itself in sentence. You use a modal before another verb in the zero conditional to express an idea such as ability, necessity, or permission.

In the zero conditional sentence structure, you can use could, can, must, or should, and their negative forms.

In the if-clause:

If you can’t see the TV, you need glasses.

If you can read this, thank a teacher!

If you must know, I’m not married.

In the result-clause:

You can’t drive a car if you don’t have a license.

If you want to go to university, you must study hard.

I can’t drive if I don’t have my glasses.

If you drink, you shouldn’t drive.

If you have celiac disease, you can’t eat wheat.

It could happen to you if you’re not careful!

You should go to the doctor if you don’t feel well.

What is the difference between using modals in the zero conditional and the first conditional?

The sentences look the same. The difference is if you are talking about general habits, facts and truths (zero conditional), or if you are talking about a possible specific situation (first conditional). Both sentence forms look the same.

I can get you a ticket to the Madonna concert if you want to go! (First conditional)

 

g. Actually, you can use any present tense as long as you use a present tense in both clauses.

You can think of the zero conditional this way:

If + present tense, present tense

You can use the present continuous tense:

If I am driving, I never answer my cell phone.

I listen to my ipod when I’m jogging.

Please don’t disturb me if I’m sleeping!

You can use the present perfect tense:

It’s easier to study when I’ve eaten a good breakfast.

If you’ve been to Europe, you know that hotel rooms there are typically small.

If you’ve never been to Europe, you should go!

 

h. And you can use past tenses in both clauses to describe past habits & past truths. Why is English so confusing???

OK, I know that I said this was the real present factual conditional at the beginning of the lesson. I didn’t want to confuse you! I wanted you to understand the form of the zero conditional and how to use it before I started talking about advanced grammar.

You use the zero conditional to talk about routines, habits, and facts. Conditional sentences connect actions, events, or situations and results.

You can also use this sentence structure to talk about connected events and results that were true in the past. If you use this sentence structure in the past, use a past tense in both clauses.

Whenever I was late for work, I took a taxi.

If I didn’t finish my homework, I wasn’t allowed to watch TV.

If I didn’t come home after school, my mother got angry.

I walked to school every day when I was young. If it rained, my mom drove me to school.

The zero conditional is one of 3 ways that you can talk about past habits or things that happened in the past. You can also use the modal verbs used to and would.

If we had a day off from school, my mom used to take us to the library.

Learn more: English Grammar: How to use “used to” to talk about past habits

I walked to school every day when I was young. If it rained, my mom would drive me to school.

This is not the second conditional or the third conditional. The second & third conditionals are unreal conditionals. They imagine situations in the present and the past that never happened.

Learn more: English Grammar: How to use “would” to talk about past habits