Conditional Sentences: What Are Conditional Sentences? Definition and Examples

By Carly Forsaith, updated on May 5, 2023

Are you wondering what conditional sentences are? If so, you've come to the right place. This article will teach you everything you need to know about when and how to use them.

In short:

  • Conditional sentences are used to discuss facts, general truths, and hypothetical situations and their consequences. 

What Are Conditional Sentences?

The conditional mood is one of five verb moods that exist in the English language. Conditional sentences are made up of a conditional clause (often referred to as the 'if clause') and a main clause (which states the consequence). In other words, a dependent clause and an independent clause.

They allow you to discuss general truths, a probable consequence of a future action, a possible consequence of an unlikely action, or the outcome of a different past action. Which of these it is will depend on the type of conditional sentence it is (there are four).

Here are some examples of conditional sentences:

If I were you, I would tell him the truth.

We might be rich now if I had taken the job.

If he wants to tell me something, he can tell me himself.

Notice how sometimes the 'if clause' comes first, and sometimes it comes second. Both these forms are correct. Just remember that if the 'if clause' comes first, you should follow it with a comma before writing the main clause.

Now let's learn about the different types of conditional sentences.

Four Types of Conditional Sentences

There are four different types of conditional sentences, each one describing a different degree of probability. They are:

  • Zero conditional
  • First conditional
  • Second conditional
  • Third conditional

We will go over each of them one by one and learn how to formulate them. Let's dive in.

Zero Conditional

Here's how to form sentences in the zero conditional:

[if] + [subject] + [action in the present indefinite tense] ; [consequence in the present indefinite]

Of course, with all types of conditional sentences, you can reverse the order of the two clauses so it looks more like this:

[consequence in the present indefinite] ; [if] + [subject] + [present indefinite tense]

The zero conditional is used for describing general truths or stating what typically happens as the result of something else

Here are some examples:

When you don't sleep enough, you get tired.

If I finish work early, I go for a walk around the park.

I only eat breakfast when I feel like it.

Notice that two of these sentences use the conjunction 'when' instead of 'if,' which is not only perfectly acceptable but also preferable in the zero conditional.

First Conditional

Here's how to form sentences in the first conditional:

[if] + [subject] + [action in the present indefinite tense] ; [consequence in the future indefinite]

The first conditional is used to talk about a probable consequence resulting from a potential event taking place. Or your intentions as a result of something else happening.

Here are some examples:

If I see her at the office, I'll say hello.

If it rains, we'll move the event indoors.

Maria will help you if I'm not here.

Second Conditional

Here's how to form sentences in the second conditional:

[if] + [subject] + [action in the past indefinite tense] ; [consequence using a modal verb + root verb]

The second conditional is used to talk about unlikely scenarios, pipe dreams, or just hypothetical consequences resulting from a hypothetical event coming true.

Here are some examples:

If a genie in a lamp offered me a superpower, I would choose invisibility. 

You might not be happier if you had more money.

Things would be simpler if we could all just be friends.

Third Conditional

Here's how to form sentences in the third conditional:

[if] + [subject] + [action in the past perfect tense] ; [consequence using a modal verb + present perfect]

The third conditional is used to talk about the consequences of a hypothetical situation in the past. In other words, you use it to talk about something impossible because it didn't happen and is in the past, so it's too late to change it. 

Here are some examples:

I wouldn't have made lasagna if I had known you're a vegetarian.

If you hadn't overwatered your plants they wouldn't have died.

If they had wanted your opinion they would have asked for it. 

Mixed Conditional

I know I said there are four types of conditional, but there's actually one more type, and it's called 'mixed conditional.' You can use it to talk about a past event/action affecting the present or a present event/action affecting the past.

Let's talk about the first one: the past changing the present. The structure is as follows:

[if] + [subject] + [action in the past perfect] ; [consequence using modal verb + root verb]

This form of conditional is used to talk about what would be true today if a past action had been different. 

Here are some examples:

If we had attended different high schools, we wouldn't be friends today.

If I hadn't worked my socks off, I wouldn't be where I am now. 

They would still hungry even if they had eaten breakfast this morning. 

Now let's look at the second one: the present changing the past. The structure is as follows:

[if] + [subject] + [action in the past indefinite] ; [consequence using modal verb + present perfect]

This form of conditional is used to discuss how a different present reality would mean a different past event or outcome.

Here are some examples:

If they were nicer we could have all been friends.

You could have had better results if you were more driven.

If planes didn't exist, many people would never have traveled.

Some Notes on Formulating Conditional Sentences

Now we've covered the basics, there are a couple more things that you should know if you want to go deeper with your understanding of conditional sentences.

If [Subject] Were To

There's a phrase that's commonly used in the 'if clause' of a conditional sentence, and that's "If [subject] were to." You can use it in the past, present or future tenses to make your sentence even more hypothetical. What you say in your "If [subject] were to" clause is particularly unthinkable. For that reason, it's mainly used to talk about negative scenarios.

Here are some examples of what that looks like in a sentence:

If you were to have been there, you would have witnessed the incident. (past tense)

If he were to speak to me that way, I would give him a piece of my mind. (present tense)

If I were to ever become president, I would make bagels free for all. (future tense)

'If' Alternatives

There are alternatives to the conjunction 'if' such as 'when,' 'should,' or 'unless,' or even sentence inversion, depending on the type of conditional you're using.

Let's start with inversion. Take a look at the following sentence in the third conditional:

If I had known it would be this complicated, I never would have started. 

You can express the exact same idea with the following sentence:

Had I known it would be this complicated, I never would have started. 

The order of the first three words has been switched up, which is why this technique is called 'inversion.' And it allows you to leave out the 'if.' So which of the two sentences is better? The truth is, they're both great sentences. The inversion method is more formal so you can use it in formal writing or settings.

As I mentioned, you can also swap out 'if' for other words.

Take a look:

If I need to be present at the meeting I'll come into the office. 

Should I need to be present at the meeting I'll come into the office. 

The above example shows you can easily replace 'if' with 'should.' Here's an example where we replace 'if' with 'unless:'

If I don't need to attend the meeting I'll stay at home.

Unless you need me to attend the meeting I'll stay at home.

Concluding Thoughts

Well, that pretty much sums it up. You now know everything you need to know to put together coherent conditional sentences. Let's summarize what we've learned:

  • Conditional sentences help express a general truth or hypothetical consequences.
  • They have an 'if' clause (dependent clause) and a consequence clause (independent clause).
  • There are four types of conditional sentences: zero, first, second and third.
  • Each type expresses a different degree of probability.
  • You can replace the word 'if' with other words or by inversion.

If you found this article helpful, I'm sure you'll enjoy our Grammar Book, a free online database full of grammar articles breaking down various English grammar concepts into digestible articles. Head there now to take your grammar knowledge to the next level!

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Written By:
Carly Forsaith
Carly Forsaith is one of the lead freelance writers for Carly is a copywriter who has been writing about the English language for over 3 years. Before that, she was a teacher in Thailand, helping people learn English as a second language. She is a total grammar nerd and spends her time spotting language errors on signs and on the internet.

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