Present perfect in the first conditional

completionconditionalsIF

The present perfect in the if-clause of a sentence in the first conditional emphasises that one action depends on the completion of another:


If I've finished writing my paper by tonight, I'll go out with my friends.

https://www.grammaring.com/present-perfect-in-the-first-conditional

Conditionals are used to refer to an action or event, that does could or might occur at some point in time.


Third conditional is formed with "if" plus "past perfect" and "would" plus present perfect.


Third conditional is used to

  • refer to hypothetical situations.
  • refer to unreal situations.
  • connect the past with another point in time.
  • connects to past with the past present or future.

Other modal verbs can also be used in third conditional.

Remember conditional clauses can be reversed with the same meaning.

Adverbs are very important to help refer to time.


Here are examples that refer to yesterday.

  • If I had traveled by plane my boat wouldn't have sunk.
  • If I had brought suntan lotion I wouldn't have gotten a sunburn.
  • If I had had stronger legs I wouldn't have fallen down.
  • I would have met you if you had asked me.
  • It would have worked better if you had repaired it.
  • He would have graduated if he had studied more.
  • I would have driven the car if it hadn't been in the repair shop.
  • I would have traveled to the moon if I had had a spaceship.


Here are examples from the past to the moment of speech;

  • If I had known you weren't coming, I wouldn't have started jumping without you.
  • If you had told me I couldn't lift this, I wouldn't have tried to do it.
  • If we had called the repairman, the door would have worked properly.
  • If we'd asked more friends to participate, there would have been more performers.
  • If I had studied singing, I wouldn't have become a part-time juggler.
  • If I had known how to fly a plane. I wouldn't have had to use my parachute.

Remember that third conditional refers to the past in the if clause.

The main clause refers to another point in time.

The main clause is also used with general thoughts without a time reference.


A very good understanding of past perfect and present perfect is required.


Adverbs and time expressions are also essential.


Third conditional is often

  • used in response to a previous statement.
  • used to give a reason for an event.


Here are examples with a future time reference.

  • If I had known you wanted to see a movie tomorrow, I'd have changed my schedule.
  • If we had met yesterday, we wouldn't have had to meet tomorrow.
  • If I'd known how dangerous this is, I wouldn't have agreed to do this tomorrow.