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 couldn't prognostic you couldn't prognostic he couldn't prognostic we couldn't prognostic you couldn't prognostic they couldn't prognostic
V-ing form
I couldn't be prognosticing you couldn't be prognosticing he couldn't be prognosticing we couldn't be prognosticing you couldn't be prognosticing they couldn't be prognosticing
Perfect
I couldn't have prognosticed you couldn't have prognosticed he couldn't have prognosticed we couldn't have prognosticed you couldn't have prognosticed they couldn't have prognosticed
V-ing perfect
I couldn't have been prognosticing you couldn't have been prognosticing he couldn't have been prognosticing we couldn't have been prognosticing you couldn't have been prognosticing they couldn't 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
couldn't I prognostic? couldn't you prognostic? couldn't he prognostic? couldn't we prognostic? couldn't you prognostic? couldn't they prognostic?
V-ing form
couldn't I be prognosticing? couldn't you be prognosticing? couldn't he be prognosticing? couldn't we be prognosticing? couldn't you be prognosticing? couldn't they be prognosticing?
Perfect
couldn't I have prognosticed? couldn't you have prognosticed? couldn't he have prognosticed? couldn't we have prognosticed? couldn't you have prognosticed? couldn't they have prognosticed?
V-ing perfect
couldn't I have been prognosticing? couldn't you have been prognosticing? couldn't he have been prognosticing? couldn't we have been prognosticing? couldn't you have been prognosticing? couldn't they have been prognosticing?