Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could dig up you could dig up she could dig up we could dig up you could dig up they could dig up
V-ing form
I could be dig uping you could be dig uping she could be dig uping we could be dig uping you could be dig uping they could be dig uping
Perfect
I could have dig uped you could have dig uped she could have dig uped we could have dig uped you could have dig uped they could have dig uped
V-ing perfect
I could have been dig uping you could have been dig uping she could have been dig uping we could have been dig uping you could have been dig uping they could have been dig uping
Negation
Simple form
I could not dig up you could not dig up she could not dig up we could not dig up you could not dig up they could not dig up
V-ing form
I could not be dig uping you could not be dig uping she could not be dig uping we could not be dig uping you could not be dig uping they could not be dig uping
Perfect
I could not have dig uped you could not have dig uped she could not have dig uped we could not have dig uped you could not have dig uped they could not have dig uped
V-ing perfect
I could not have been dig uping you could not have been dig uping she could not have been dig uping we could not have been dig uping you could not have been dig uping they could not have been dig uping
Interrogative form
Simple form
could I dig up? could you dig up? could she dig up? could we dig up? could you dig up? could they dig up?
V-ing form
could I be dig uping? could you be dig uping? could she be dig uping? could we be dig uping? could you be dig uping? could they be dig uping?
Perfect
could I have dig uped? could you have dig uped? could she have dig uped? could we have dig uped? could you have dig uped? could they have dig uped?
V-ing perfect
could I have been dig uping? could you have been dig uping? could she have been dig uping? could we have been dig uping? could you have been dig uping? could they have been dig uping?
Interro-negative form
Simple form
could I not dig up? could you not dig up? could she not dig up? could we not dig up? could you not dig up? could they not dig up?
V-ing form
could I not be dig uping? could you not be dig uping? could she not be dig uping? could we not be dig uping? could you not be dig uping? could they not be dig uping?
Perfect
could I not have dig uped? could you not have dig uped? could she not have dig uped? could we not have dig uped? could you not have dig uped? could they not have dig uped?
V-ing perfect
could I not have been dig uping? could you not have been dig uping? could she not have been dig uping? could we not have been dig uping? could you not have been dig uping? could they not have been dig uping?