English verb conjugation
COULD FOREWARN

Regular verb: forewarn - forewarned - forewarned

Affirmation

Simple form	V-ing form
I could forewarn you could forewarn he could forewarn we could forewarn you could forewarn they could forewarn	I could be forewarning you could be forewarning he could be forewarning we could be forewarning you could be forewarning they could be forewarning
Perfect	V-ing perfect
I could have forewarned you could have forewarned he could have forewarned we could have forewarned you could have forewarned they could have forewarned	I could have been forewarning you could have been forewarning he could have been forewarning we could have been forewarning you could have been forewarning they could have been forewarning

Negation

Simple form	V-ing form
I couldn't forewarn you couldn't forewarn he couldn't forewarn we couldn't forewarn you couldn't forewarn they couldn't forewarn	I couldn't be forewarning you couldn't be forewarning he couldn't be forewarning we couldn't be forewarning you couldn't be forewarning they couldn't be forewarning
Perfect	V-ing perfect
I couldn't have forewarned you couldn't have forewarned he couldn't have forewarned we couldn't have forewarned you couldn't have forewarned they couldn't have forewarned	I couldn't have been forewarning you couldn't have been forewarning he couldn't have been forewarning we couldn't have been forewarning you couldn't have been forewarning they couldn't have been forewarning

Interrogative form

Simple form	V-ing form
could I forewarn? could you forewarn? could he forewarn? could we forewarn? could you forewarn? could they forewarn?	could I be forewarning? could you be forewarning? could he be forewarning? could we be forewarning? could you be forewarning? could they be forewarning?
Perfect	V-ing perfect
could I have forewarned? could you have forewarned? could he have forewarned? could we have forewarned? could you have forewarned? could they have forewarned?	could I have been forewarning? could you have been forewarning? could he have been forewarning? could we have been forewarning? could you have been forewarning? could they have been forewarning?

Interro-negative form

Simple form	V-ing form
couldn't I forewarn? couldn't you forewarn? couldn't he forewarn? couldn't we forewarn? couldn't you forewarn? couldn't they forewarn?	couldn't I be forewarning? couldn't you be forewarning? couldn't he be forewarning? couldn't we be forewarning? couldn't you be forewarning? couldn't they be forewarning?
Perfect	V-ing perfect
couldn't I have forewarned? couldn't you have forewarned? couldn't he have forewarned? couldn't we have forewarned? couldn't you have forewarned? couldn't they have forewarned?	couldn't I have been forewarning? couldn't you have been forewarning? couldn't he have been forewarning? couldn't we have been forewarning? couldn't you have been forewarning? couldn't they have been forewarning?