What Are Third Conditionals?
The third conditional is a form of the hypothetical statement that is used to talk about an unfulfilled dream, wish, or some event that did not happen in the past.
It is as if we are describing or imagining a different version of the past. Take a look at the examples below:
Here in this example, the statement is about the time he/she wished to go to the university and study but it has been left unfulfilled.
The structure of the third conditional is:
If you want to change the statement to a negative one, remember to add not before have in the sentence.
Note that wouldn't have is the short from of
If you want to state the main clause first, there is no need to add commas in between the two sentences.
She should've called the police
This type of hypothetical statement is used when we want to talk about an unreal situation that could happen in the past but did not or it's a dream that was not fulfilled.
Here as you can see, we are talking about an unreal past event.
Second Conditionals vs. Third Conditionals
The main difference between these two structures is that the third conditional form is used when we want to talk about a different version of the past. Something that could happen but did not, in the second conditional sentence, we talk about an unreal situation in the present or in the future.
Compare the following examples:
Here as you can see, we are talking about regretting something in the past.
In this example, there is a possibility to happen in the future.
Also, these two structures differ. In the second conditional, we use simple past + would/could/should, but in the third conditional, the structure is past perfect + would/could/should + have + the past participle form of the verb.
Notice the difference in the following examples: