Conditional Clauses in English Grammar

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Conditional clauses, also known as if clauses or conditional sentences, express an imagined situation or condition and the possible result of that situation. They consist of a main clause and a conditional dependent clause. Conditional clauses are often introduced by the word if, although sometimes other words can be used. Check out our pages on conjunctions and if or when for more information.

Learn about the different types of conditional sentences in English grammar, then test out your grammar skills in the exercises.


Mother: “Greg and I often bake cakes together.”

Greg: “Of course. Whenever I have time, I help you.”

Mother: “Greg, I want to make a cake this afternoon. Will you help me?”

Greg: “If I have time, I’ll help you.

Bild 1

Mother: “Greg, I am going to make the cake now. Can you help me?”

Greg: “If I had time, I’d help you. But I have to do my homework.”

Bild 2

Mother: “Now I’ve made the cake myself. Why didn’t you help me?”

Greg: “If I’d had time, I would have helped you. But I had to do my homework.”

Bild 3

How to use conditionals

Zero Conditional

The zero conditional expresses general truths that always happen providing that a certain condition is met. It talks about facts, habits and rules.

To construct the zero conditional, we use the simple present in both the if clause and the result clause.

If you leave ice cream in the sun, it melts.

In the zero conditional if and when can be used interchangeably.

Harry feels better if he exercises. = Harry feels better when he exercises.

We can also use whenever. This means at any time or every time when.

Whenever it is warm, I go to the beach.

First Conditional

We use the first conditional to talk about an action that could take place under certain conditions in the present or the future. It is also called the real conditional because it reflects a realistic possibility.

To construct the first conditional, use the formula: if + present simple, will + infinitive.

If I have time, I will help you.
it is possible that I will have time

Typical contexts for the first conditional include: warnings and threats, future consequences, predictions, promises, superstitions, negotiations etc.

If you keep spending money you will get in trouble! (warning)
If you behave nicely for the next hour, I’ll give you a toy. (negotiation)
If things don’t change, the people will protest. (prediction)
You get seven years of bad luck if you break a mirror. (superstition)

Second Conditional

The second conditional talks about an unlikely or imaginary event (expressed in the if clause) and its result. It imagines that the present or future is different to how it really is. For this reason, it is also known as the unreal conditional.

To construct the second conditional, use the formula: if + simple past, would + infinitive

If I had time, I would help you.
I already know that I won’t have time

Typical contexts for the second conditional include: asking hypothetical questions, imagining life as different and giving advice.

What would you do if you met your favourite celebrity in the street? (hypothetical question)
If I didn’t have so much work, I’d take a long vacation. (imagining life as different)
If I were you, I’d wait a while before calling. (advice)

If I was/were you …

When the be is used in the second conditional, we can use both was and were for the first and third person singular forms. There is no change in meaning, although were is sometimes considered more formal.

If I were you, I would not do this.
I wouldn’t do that if I was you.

Third Conditional

The third conditional looks back at past situations and imagines a different outcome. It talks about a past situation that didn’t happen and therefore describes an impossible result – we cannot go back in time to change the outcome.

To construct the third conditional use the formula: if + past perfect, would have + past participle

If I had had time, I would have helped you.
I didn’t have time and I can’t change this

We use the third conditional to express regrets, give criticism and generally reflect on the past.

If I had known more, I would have done things differently. (regret)
I would have been happier if your customer service had been better. (criticism)

Modal Verbs in Conditional Sentences

In place of will/would in conditional sentences, we can use use other modal verbs. However, using other verbs changes the meaning of the sentence.

If I have time, I can/could/may/might help you.
If I had time, I could/might help you.
If I had had time, I could/might have helped you.

Notes on Sentence Structure

We can change the order of the two clauses. When the sentence starts with the if clause, we put a comma before the main clause.

If I have time, I will help you.
If I had time, I would help you.
If I had had time, I would have helped you.

When the sentence starts with the main clause, we don’t use a comma.

I will help you if I have time.
I would help you if I had time.
I would have helped you if I had had time.

Learn more about punctuation and comma usage in the writing school section of the website.