English verb conjugation
COULD FOREWARN

Regular verb: forewarn - forewarned - forewarned

Affirmation

Simple form	V-ing form
I could forewarn you could forewarn she could forewarn we could forewarn you could forewarn they could forewarn	I could be forewarning you could be forewarning she 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 she 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 she 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 she 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 she 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 she 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 she 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 she forewarn? could we forewarn? could you forewarn? could they forewarn?	could I be forewarning? could you be forewarning? could she 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 she 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 she 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 she 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 she 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 she 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 she have been forewarning? couldn't we have been forewarning? couldn't you have been forewarning? couldn't they have been forewarning?