English verb conjugation
COULD DOFF

Regular verb: doff - doffed - doffed

Affirmation

Simple form	V-ing form
I could doff you could doff she could doff we could doff you could doff they could doff	I could be doffing you could be doffing she could be doffing we could be doffing you could be doffing they could be doffing
Perfect	V-ing perfect
I could have doffed you could have doffed she could have doffed we could have doffed you could have doffed they could have doffed	I could have been doffing you could have been doffing she could have been doffing we could have been doffing you could have been doffing they could have been doffing

Negation

Simple form	V-ing form
I could not doff you could not doff she could not doff we could not doff you could not doff they could not doff	I could not be doffing you could not be doffing she could not be doffing we could not be doffing you could not be doffing they could not be doffing
Perfect	V-ing perfect
I could not have doffed you could not have doffed she could not have doffed we could not have doffed you could not have doffed they could not have doffed	I could not have been doffing you could not have been doffing she could not have been doffing we could not have been doffing you could not have been doffing they could not have been doffing

Interrogative form

Simple form	V-ing form
could I doff? could you doff? could she doff? could we doff? could you doff? could they doff?	could I be doffing? could you be doffing? could she be doffing? could we be doffing? could you be doffing? could they be doffing?
Perfect	V-ing perfect
could I have doffed? could you have doffed? could she have doffed? could we have doffed? could you have doffed? could they have doffed?	could I have been doffing? could you have been doffing? could she have been doffing? could we have been doffing? could you have been doffing? could they have been doffing?

Interro-negative form

Simple form	V-ing form
could I not doff? could you not doff? could she not doff? could we not doff? could you not doff? could they not doff?	could I not be doffing? could you not be doffing? could she not be doffing? could we not be doffing? could you not be doffing? could they not be doffing?
Perfect	V-ing perfect
could I not have doffed? could you not have doffed? could she not have doffed? could we not have doffed? could you not have doffed? could they not have doffed?	could I not have been doffing? could you not have been doffing? could she not have been doffing? could we not have been doffing? could you not have been doffing? could they not have been doffing?