English verb conjugation
COULD TACK

Regular verb: tack - tacked - tacked

Affirmation

Simple form	V-ing form
I could tack you could tack he could tack we could tack you could tack they could tack	I could be tacking you could be tacking he could be tacking we could be tacking you could be tacking they could be tacking
Perfect	V-ing perfect
I could have tacked you could have tacked he could have tacked we could have tacked you could have tacked they could have tacked	I could have been tacking you could have been tacking he could have been tacking we could have been tacking you could have been tacking they could have been tacking

Negation

Simple form	V-ing form
I could not tack you could not tack he could not tack we could not tack you could not tack they could not tack	I could not be tacking you could not be tacking he could not be tacking we could not be tacking you could not be tacking they could not be tacking
Perfect	V-ing perfect
I could not have tacked you could not have tacked he could not have tacked we could not have tacked you could not have tacked they could not have tacked	I could not have been tacking you could not have been tacking he could not have been tacking we could not have been tacking you could not have been tacking they could not have been tacking

Interrogative form

Simple form	V-ing form
could I tack? could you tack? could he tack? could we tack? could you tack? could they tack?	could I be tacking? could you be tacking? could he be tacking? could we be tacking? could you be tacking? could they be tacking?
Perfect	V-ing perfect
could I have tacked? could you have tacked? could he have tacked? could we have tacked? could you have tacked? could they have tacked?	could I have been tacking? could you have been tacking? could he have been tacking? could we have been tacking? could you have been tacking? could they have been tacking?

Interro-negative form

Simple form	V-ing form
could I not tack? could you not tack? could he not tack? could we not tack? could you not tack? could they not tack?	could I not be tacking? could you not be tacking? could he not be tacking? could we not be tacking? could you not be tacking? could they not be tacking?
Perfect	V-ing perfect
could I not have tacked? could you not have tacked? could he not have tacked? could we not have tacked? could you not have tacked? could they not have tacked?	could I not have been tacking? could you not have been tacking? could he not have been tacking? could we not have been tacking? could you not have been tacking? could they not have been tacking?