English verb conjugation
COULD RESTACK

Regular verb: restack - restacked - restacked

Affirmation

Simple form	V-ing form
I could restack you could restack he could restack we could restack you could restack they could restack	I could be restacking you could be restacking he could be restacking we could be restacking you could be restacking they could be restacking
Perfect	V-ing perfect
I could have restacked you could have restacked he could have restacked we could have restacked you could have restacked they could have restacked	I could have been restacking you could have been restacking he could have been restacking we could have been restacking you could have been restacking they could have been restacking

Negation

Simple form	V-ing form
I could not restack you could not restack he could not restack we could not restack you could not restack they could not restack	I could not be restacking you could not be restacking he could not be restacking we could not be restacking you could not be restacking they could not be restacking
Perfect	V-ing perfect
I could not have restacked you could not have restacked he could not have restacked we could not have restacked you could not have restacked they could not have restacked	I could not have been restacking you could not have been restacking he could not have been restacking we could not have been restacking you could not have been restacking they could not have been restacking

Interrogative form

Simple form	V-ing form
could I restack? could you restack? could he restack? could we restack? could you restack? could they restack?	could I be restacking? could you be restacking? could he be restacking? could we be restacking? could you be restacking? could they be restacking?
Perfect	V-ing perfect
could I have restacked? could you have restacked? could he have restacked? could we have restacked? could you have restacked? could they have restacked?	could I have been restacking? could you have been restacking? could he have been restacking? could we have been restacking? could you have been restacking? could they have been restacking?

Interro-negative form

Simple form	V-ing form
could I not restack? could you not restack? could he not restack? could we not restack? could you not restack? could they not restack?	could I not be restacking? could you not be restacking? could he not be restacking? could we not be restacking? could you not be restacking? could they not be restacking?
Perfect	V-ing perfect
could I not have restacked? could you not have restacked? could he not have restacked? could we not have restacked? could you not have restacked? could they not have restacked?	could I not have been restacking? could you not have been restacking? could he not have been restacking? could we not have been restacking? could you not have been restacking? could they not have been restacking?