English verb conjugation
COULD UNTACK

Regular verb: untack - untacked - untacked

Affirmation

Simple form	V-ing form
I could untack you could untack he could untack we could untack you could untack they could untack	I could be untacking you could be untacking he could be untacking we could be untacking you could be untacking they could be untacking
Perfect	V-ing perfect
I could have untacked you could have untacked he could have untacked we could have untacked you could have untacked they could have untacked	I could have been untacking you could have been untacking he could have been untacking we could have been untacking you could have been untacking they could have been untacking

Negation

Simple form	V-ing form
I couldn't untack you couldn't untack he couldn't untack we couldn't untack you couldn't untack they couldn't untack	I couldn't be untacking you couldn't be untacking he couldn't be untacking we couldn't be untacking you couldn't be untacking they couldn't be untacking
Perfect	V-ing perfect
I couldn't have untacked you couldn't have untacked he couldn't have untacked we couldn't have untacked you couldn't have untacked they couldn't have untacked	I couldn't have been untacking you couldn't have been untacking he couldn't have been untacking we couldn't have been untacking you couldn't have been untacking they couldn't have been untacking

Interrogative form

Simple form	V-ing form
could I untack? could you untack? could he untack? could we untack? could you untack? could they untack?	could I be untacking? could you be untacking? could he be untacking? could we be untacking? could you be untacking? could they be untacking?
Perfect	V-ing perfect
could I have untacked? could you have untacked? could he have untacked? could we have untacked? could you have untacked? could they have untacked?	could I have been untacking? could you have been untacking? could he have been untacking? could we have been untacking? could you have been untacking? could they have been untacking?

Interro-negative form

Simple form	V-ing form
couldn't I untack? couldn't you untack? couldn't he untack? couldn't we untack? couldn't you untack? couldn't they untack?	couldn't I be untacking? couldn't you be untacking? couldn't he be untacking? couldn't we be untacking? couldn't you be untacking? couldn't they be untacking?
Perfect	V-ing perfect
couldn't I have untacked? couldn't you have untacked? couldn't he have untacked? couldn't we have untacked? couldn't you have untacked? couldn't they have untacked?	couldn't I have been untacking? couldn't you have been untacking? couldn't he have been untacking? couldn't we have been untacking? couldn't you have been untacking? couldn't they have been untacking?