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