Formation of the past conditional simple

The past conditional simple consists of three parts, which are the auxiliary verbs ‘would’ + ‘have’ and the past participle of the corresponding main verb. Due to its use with ‘have’, it is also often called perfect conditional. In the majority of cases, it is utilised in the third conditional sentence (if-clause type 3).

• Examples of forming the past conditional simple:
  • “I would have done it.”
    • This is a positive sentence that illustrates a situation that did not occur in the past.
  • “If Mike had revised more for the exam, he wouldn’t have failed it.”
    • Here, it is part of the if-clause type 3.

Verb forms of the past conditional simple

Example verb: ‘to see’

Positive/affirmative sentences

Person/​pronoun	Positive	Short form	Interrogative form	Short form of question
I	You would have seen.	You’d have seen. or You would’ve seen.	Would you have seen?	–
you (singular)
he/​she/​it
we/​you/​they

Negative sentences

Person/​pronoun	Negative	Short form	Interrogative form	Short form of question
I	He would not have seen.	He wouldn’t have seen. or He’d not have seen.*	Would he not have seen?	Wouldn’t he have seen?
you (singular)
he/​she/​it
we/​you/​they

* This form is not as common as the other one.

Explanations relating to the ‘Formation of the past conditional simple’

The following additional explanations are related to the topic ‘Conjugation & verb forms of the past conditional simple’ and can also help you:

• Formation of the past conditional continuous
• Use of the if-clause type 1
• Use of the if-clause type 2
• Main/full verbs in English
• Exercise 1: if-clause type 3 (conditional 3)