Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could prognostic you could prognostic he could prognostic we could prognostic you could prognostic they could prognostic
V-ing form
I could be prognosticing you could be prognosticing he could be prognosticing we could be prognosticing you could be prognosticing they could be prognosticing
Perfect
I could have prognosticed you could have prognosticed he could have prognosticed we could have prognosticed you could have prognosticed they could have prognosticed
V-ing perfect
I could have been prognosticing you could have been prognosticing he could have been prognosticing we could have been prognosticing you could have been prognosticing they could have been prognosticing
Negation
Simple form
I could not prognostic you could not prognostic he could not prognostic we could not prognostic you could not prognostic they could not prognostic
V-ing form
I could not be prognosticing you could not be prognosticing he could not be prognosticing we could not be prognosticing you could not be prognosticing they could not be prognosticing
Perfect
I could not have prognosticed you could not have prognosticed he could not have prognosticed we could not have prognosticed you could not have prognosticed they could not have prognosticed
V-ing perfect
I could not have been prognosticing you could not have been prognosticing he could not have been prognosticing we could not have been prognosticing you could not have been prognosticing they could not have been prognosticing
Interrogative form
Simple form
could I prognostic? could you prognostic? could he prognostic? could we prognostic? could you prognostic? could they prognostic?
V-ing form
could I be prognosticing? could you be prognosticing? could he be prognosticing? could we be prognosticing? could you be prognosticing? could they be prognosticing?
Perfect
could I have prognosticed? could you have prognosticed? could he have prognosticed? could we have prognosticed? could you have prognosticed? could they have prognosticed?
V-ing perfect
could I have been prognosticing? could you have been prognosticing? could he have been prognosticing? could we have been prognosticing? could you have been prognosticing? could they have been prognosticing?
Interro-negative form
Simple form
could I not prognostic? could you not prognostic? could he not prognostic? could we not prognostic? could you not prognostic? could they not prognostic?
V-ing form
could I not be prognosticing? could you not be prognosticing? could he not be prognosticing? could we not be prognosticing? could you not be prognosticing? could they not be prognosticing?
Perfect
could I not have prognosticed? could you not have prognosticed? could he not have prognosticed? could we not have prognosticed? could you not have prognosticed? could they not have prognosticed?
V-ing perfect
could I not have been prognosticing? could you not have been prognosticing? could he not have been prognosticing? could we not have been prognosticing? could you not have been prognosticing? could they not have been prognosticing?