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