Conditional III 

This article dives into the Conditional III, like 'If he had studied, he would have passed the exam'. Detailed explanations and a quiz are included to test your knowledge.

"Conditional III" in English Grammar

What Are Third Conditionals?

The third conditional is a type of conditional sentence that deals with hypothetical or unreal situations in the past that did not happen. It describes a different version of the past that could have happened if certain conditions were met. The third conditional is often used to talk about unfulfilled dreams, regrets, or missed opportunities.

Third Conditional: Structure

The structure of a third conditional sentence includes a condition clause that presents a hypothetical past condition using the past perfect tense, and a main clause that indicates the hypothetical past result using the modal verb 'would' followed by the auxiliary 'have,' and the main verb in its past participle form. Thus, the structure is as follows:

[condition marker + past perfect] + [could/would/might + "have" + past participle]

Take a look at some examples:

Example

If I had remembered her number, I would have called her.

By using the third conditional, the speaker is imagining a different past where they remembered her number.

If he hadn't eaten that spoiled fish, he wouldn't have been sick.

The sentence indicates that in reality he ate that spoiled fish.

Punctuation

The order of clauses in a conditional sentence does not affect the meaning of the sentence, but it affects use of punctuation. If the condition clause comes at the beginning of the sentence, it must be followed by a comma (,). For example:

Example

If you had told me you were coming, I would have made dinner.

However, if the sentence begins with the main clause, there is no need to put a comma between the two clauses. For example:

Example

I would have made dinner if you had told me you were coming.

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Modals

Conditional tenses are used to create the main clause of a conditional sentence, which expresses hypothetical or unlikely situations. Modal verbs like could, would, and might** are examples of modal verbs commonly used in third conditionals. Each of these modals indicates a specific meaning. Compare the following sentences:

Example

If he had finished high school, he would have gone to college.

'Would' indicates that if he had finished high school, he would have certainly gone to college.

If he had finished high school, he might have gone to college.

'Might' indicates that even if he had finished high school, it is not certain that he would have gone to college.

If he had finished high school, he could have gone to college.

'Could' indicates that if he had finished high school, he would have been able to go to college.

Condition Markers

The most common condition markers in third conditionals are 'if' and 'unless.' 'Unless' introduces a negative condition which should not be met for the result to happen. It is the equivalent of 'if...not.' Here are some examples:

Example

If you had called me, I would have helped.

Unless you had interfered, nothing would have changed.

This sentence is equal to "If you had not interfered, nothing would have changed."

You can also form third conditional sentences using inversion of the auxiliary 'had.' In this case, there is no need to use the common condition markers like 'if' and 'unless.' For example:

Example

Had you called me, I would have helped.

Had they known, they might have acted differently.

Zero Marker

You can use a past participle at the beginning of the condition clause to introduce a passive condition, without any condition marker or inversion. Keep in mind that this structure only works with verbs that can be made passive. For example:

Example

Given more time, they would have finished the project.

This is equal to "If you had given them more time, they would have finished the project" which follows the third conditional structure.

Not warned about the danger, they would have entered the area.

Or "If no one had warned them about the danger, they would have entered the area."

Third Conditionals vs. Second Conditionals

The main difference between the second and third conditional structures is that the third conditional is used to talk about a hypothetical or unreal situation in the past that did not actually happen. On the other hand, the second conditional is used to talk about an unreal situation in the present or future that is unlikely to happen.
The two also differ in terms of structure, where the second conditional uses simple past + would/could/might+ base form of the verb, but the third conditional consists of past perfect + would/could/might+ have + the past participle form of the verb.
Compare these two sentences:

Example

If I had won one million dollars, I would have bought a house.

This is an impossible situations, because it never happened and the past event cannot be changed.

If I won one million dollars, I would buy a house.

Here, the condition is not impossible, but it is improbable.

Review

When we use third conditional, we are talking about the hypothetical result of something that did NOT happen. In fact, we are imagining a different past.
Third conditional sentences follow the structure below:

condition clause

past perfect

main clause

could/would/should + have + past participle

Example

If I had remembered her number, I would have called her.

The table below summarizes the differences between second and third conditionals:

meaning

structure

second

we are imagining a hypothetical situation in the present or future.

[past simple] + [modal + base verb]

third

we are imagining a hypothetical situation in the past.

[past perfect] + [modal + have + past participle]

Quiz:


1.

Sort the words to form a third conditional sentence with a passive condition.

have
clear
would
,
they
succeeded
instructions
given
.
2.

Which option expresses higher level of certainty regarding the result?

A

If she had taken the job, she would have moved to Paris.

B

If she had taken the job, she might have moved to Paris.

C

If she had taken the job, she could have moved to Paris.

D

If she had taken the job, she should have moved to Paris.

3.

Match each sentence with the corresponding description.

Had we taken the earlier train, we could have arrived by noon.
Unless you had warned me, I would have made the same mistake.
Left unattended, the documents would have been stolen.
If she had checked her messages, she would have known about it.
Third conditional using inversion
Third conditional with negative condition
Third conditional with passive condition
Regular third conditional
4.

Fill the blanks with the correct form of the verb in parentheses.

She

(not/miss) the flight if she

(leave) earlier.

If they

(invite) us, we

(might/go) to the party.

(you/arrive) on time, you

(see) the opening act.

(give) proper instructions, the team

(complete) the project.

5.

What is the main structural difference between the second and third conditional sentences?

A

Second conditional: past perfect, Third conditional: past simple

B

Third conditional: present/future simple, Second conditional: past simple

C

Second conditional: simple past + would, Third conditional: past perfect + would have

D

Second conditional: always "would," Third conditional: "could" or "might"

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Zero Conditional

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'If you don't eat or drink, you die'. 'If you heat water, it boils'. Zero conditional is used to talk about facts or situations which are always true.

Conditional I

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We use the conditional Type 1 when we want to talk about situations we believe are real or possible in the future. 'If I study hard, I'll pass the exam.'

Conditional II

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Type 2 conditional sentences talk about situations that are hypothetical. There is a possibility that the condition will be fulfilled.

Mixed Conditional

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Sometimes the two parts of a conditional sentence refer to different times. This is called a mixed conditional. Ready to learn?
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