English verb conjugation COULD STACK

Regular verb: stack - stacked - stacked


Affirmation

Simple form

I could stack
you could stack
he could stack
we could stack
you could stack
they could stack

V-ing form

I could be stacking
you could be stacking
he could be stacking
we could be stacking
you could be stacking
they could be stacking

Perfect

I could have stacked
you could have stacked
he could have stacked
we could have stacked
you could have stacked
they could have stacked

V-ing perfect

I could have been stacking
you could have been stacking
he could have been stacking
we could have been stacking
you could have been stacking
they could have been stacking

Negation

Simple form

I could not stack
you could not stack
he could not stack
we could not stack
you could not stack
they could not stack

V-ing form

I could not be stacking
you could not be stacking
he could not be stacking
we could not be stacking
you could not be stacking
they could not be stacking

Perfect

I could not have stacked
you could not have stacked
he could not have stacked
we could not have stacked
you could not have stacked
they could not have stacked

V-ing perfect

I could not have been stacking
you could not have been stacking
he could not have been stacking
we could not have been stacking
you could not have been stacking
they could not have been stacking

Interrogative form

Simple form

could I stack?
could you stack?
could he stack?
could we stack?
could you stack?
could they stack?

V-ing form

could I be stacking?
could you be stacking?
could he be stacking?
could we be stacking?
could you be stacking?
could they be stacking?

Perfect

could I have stacked?
could you have stacked?
could he have stacked?
could we have stacked?
could you have stacked?
could they have stacked?

V-ing perfect

could I have been stacking?
could you have been stacking?
could he have been stacking?
could we have been stacking?
could you have been stacking?
could they have been stacking?

Interro-negative form

Simple form

could I not stack?
could you not stack?
could he not stack?
could we not stack?
could you not stack?
could they not stack?

V-ing form

could I not be stacking?
could you not be stacking?
could he not be stacking?
could we not be stacking?
could you not be stacking?
could they not be stacking?

Perfect

could I not have stacked?
could you not have stacked?
could he not have stacked?
could we not have stacked?
could you not have stacked?
could they not have stacked?

V-ing perfect

could I not have been stacking?
could you not have been stacking?
could he not have been stacking?
could we not have been stacking?
could you not have been stacking?
could they not have been stacking?