I could forage you could forage he could forage we could forage you could forage they could forage
V-ing form
I could be foraging you could be foraging he could be foraging we could be foraging you could be foraging they could be foraging
Perfect
I could have foraged you could have foraged he could have foraged we could have foraged you could have foraged they could have foraged
V-ing perfect
I could have been foraging you could have been foraging he could have been foraging we could have been foraging you could have been foraging they could have been foraging
Negation
Simple form
I couldn't forage you couldn't forage he couldn't forage we couldn't forage you couldn't forage they couldn't forage
V-ing form
I couldn't be foraging you couldn't be foraging he couldn't be foraging we couldn't be foraging you couldn't be foraging they couldn't be foraging
Perfect
I couldn't have foraged you couldn't have foraged he couldn't have foraged we couldn't have foraged you couldn't have foraged they couldn't have foraged
V-ing perfect
I couldn't have been foraging you couldn't have been foraging he couldn't have been foraging we couldn't have been foraging you couldn't have been foraging they couldn't have been foraging
Interrogative form
Simple form
could I forage? could you forage? could he forage? could we forage? could you forage? could they forage?
V-ing form
could I be foraging? could you be foraging? could he be foraging? could we be foraging? could you be foraging? could they be foraging?
Perfect
could I have foraged? could you have foraged? could he have foraged? could we have foraged? could you have foraged? could they have foraged?
V-ing perfect
could I have been foraging? could you have been foraging? could he have been foraging? could we have been foraging? could you have been foraging? could they have been foraging?
Interro-negative form
Simple form
couldn't I forage? couldn't you forage? couldn't he forage? couldn't we forage? couldn't you forage? couldn't they forage?
V-ing form
couldn't I be foraging? couldn't you be foraging? couldn't he be foraging? couldn't we be foraging? couldn't you be foraging? couldn't they be foraging?
Perfect
couldn't I have foraged? couldn't you have foraged? couldn't he have foraged? couldn't we have foraged? couldn't you have foraged? couldn't they have foraged?
V-ing perfect
couldn't I have been foraging? couldn't you have been foraging? couldn't he have been foraging? couldn't we have been foraging? couldn't you have been foraging? couldn't they have been foraging?