I could brew you could brew he could brew we could brew you could brew they could brew
V-ing form
I could be brewing you could be brewing he could be brewing we could be brewing you could be brewing they could be brewing
Perfect
I could have brewed you could have brewed he could have brewed we could have brewed you could have brewed they could have brewed
V-ing perfect
I could have been brewing you could have been brewing he could have been brewing we could have been brewing you could have been brewing they could have been brewing
Negation
Simple form
I could not brew you could not brew he could not brew we could not brew you could not brew they could not brew
V-ing form
I could not be brewing you could not be brewing he could not be brewing we could not be brewing you could not be brewing they could not be brewing
Perfect
I could not have brewed you could not have brewed he could not have brewed we could not have brewed you could not have brewed they could not have brewed
V-ing perfect
I could not have been brewing you could not have been brewing he could not have been brewing we could not have been brewing you could not have been brewing they could not have been brewing
Interrogative form
Simple form
could I brew? could you brew? could he brew? could we brew? could you brew? could they brew?
V-ing form
could I be brewing? could you be brewing? could he be brewing? could we be brewing? could you be brewing? could they be brewing?
Perfect
could I have brewed? could you have brewed? could he have brewed? could we have brewed? could you have brewed? could they have brewed?
V-ing perfect
could I have been brewing? could you have been brewing? could he have been brewing? could we have been brewing? could you have been brewing? could they have been brewing?
Interro-negative form
Simple form
could I not brew? could you not brew? could he not brew? could we not brew? could you not brew? could they not brew?
V-ing form
could I not be brewing? could you not be brewing? could he not be brewing? could we not be brewing? could you not be brewing? could they not be brewing?
Perfect
could I not have brewed? could you not have brewed? could he not have brewed? could we not have brewed? could you not have brewed? could they not have brewed?
V-ing perfect
could I not have been brewing? could you not have been brewing? could he not have been brewing? could we not have been brewing? could you not have been brewing? could they not have been brewing?