Conditionals

What is a conditional?

A conditional sentence tells us that one thing depends on another. It usually has two parts:

• The condition: the if part. It says what needs to be true.
• The result: what happens because of it.

If it snows, we will build a snowman.

• Condition: if it snows
• Result: we will build a snowman

Conditionals help us talk about facts, plans, wishes, imagination and regrets. There are four main types.

The zero conditional: facts

The zero conditional is for things that are always true, such as science facts and habits.

Pattern: If + present, present

• If you heat water to 100°C, it boils.
• If plants don’t get water, they die.
• If I eat too much candy, I get a stomach ache.

You can swap if for when and the meaning stays the same: When you heat ice, it melts.

The first conditional: real possibilities

The first conditional is for real situations that might happen in the future.

Pattern: If + present, will + verb

• If it rains tomorrow, we will stay inside.
• If you study, you will do well on the test.
• If we hurry, we will catch the bus.

Notice: the if part uses the present tense even though it is about the future. Do not say If it will rain.

The second conditional: imagination

The second conditional is for unreal or imaginary situations, now or in the future. These things are not true or are very unlikely.

Pattern: If + past, would + verb

• If I had a million dollars, I would buy an island.
• If dogs could talk, they would ask for more treats.
• If I were a bird, I would fly over the ocean.

In careful writing, use were for every subject in the second conditional: If I were you, If she were taller. This is called the subjunctive mood.

The third conditional: the past that didn’t happen

The third conditional imagines a different past. It talks about something that did not happen and its imaginary result. It is often used for regrets.

Pattern: If + had + past participle, would have + past participle

• If I had studied, I would have passed the test. (I didn’t study, and I didn’t pass.)
• If we had left earlier, we would have caught the train.
• If she had seen the sign, she would have stopped.

Comparing all four

Changing the order

The if part can come first or second.

• If it rains, we will stay home.
• We will stay home if it rains.

When the if clause comes first, put a comma after it. When it comes second, you usually do not need a comma.

Other words for if

Conditionals can also use unless (if not), as long as, provided that and in case.

• We will go to the park unless it rains. (= if it doesn’t rain)
• You can borrow my bike as long as you return it.

Common mistakes

• Using will in the if clause. ✗ If it will snow, we will ski. → ✓ If it snows, we will ski.
• Mixing the patterns. ✗ If I had wings, I will fly. → ✓ If I had wings, I would fly.
• Forgetting have in the third conditional. ✗ I would went. → ✓ I would have gone.
• Writing would of. It sounds like would’ve, but the correct form is would have.

Try it yourself

Name the type of conditional:

1. If you drop a glass, it breaks.
2. If I see Sam, I will tell him.
3. If I were invisible, I would sneak into the kitchen.
4. If they had practised, they would have won.

Then finish these: If I could have any pet, … and If it is sunny on Saturday, …

Answers: zero, first, second, third.

Quick recap

• A conditional has a condition (the if part) and a result.
• Zero = facts; first = real future; second = imaginary; third = imaginary past.
• Never use will inside the if clause.
• Use a comma when the if clause comes first.