I could bin you could bin she could bin we could bin you could bin they could bin
V-ing form
I could be bining you could be bining she could be bining we could be bining you could be bining they could be bining
Perfect
I could have bined you could have bined she could have bined we could have bined you could have bined they could have bined
V-ing perfect
I could have been bining you could have been bining she could have been bining we could have been bining you could have been bining they could have been bining
Negation
Simple form
I couldn't bin you couldn't bin she couldn't bin we couldn't bin you couldn't bin they couldn't bin
V-ing form
I couldn't be bining you couldn't be bining she couldn't be bining we couldn't be bining you couldn't be bining they couldn't be bining
Perfect
I couldn't have bined you couldn't have bined she couldn't have bined we couldn't have bined you couldn't have bined they couldn't have bined
V-ing perfect
I couldn't have been bining you couldn't have been bining she couldn't have been bining we couldn't have been bining you couldn't have been bining they couldn't have been bining
Interrogative form
Simple form
could I bin? could you bin? could she bin? could we bin? could you bin? could they bin?
V-ing form
could I be bining? could you be bining? could she be bining? could we be bining? could you be bining? could they be bining?
Perfect
could I have bined? could you have bined? could she have bined? could we have bined? could you have bined? could they have bined?
V-ing perfect
could I have been bining? could you have been bining? could she have been bining? could we have been bining? could you have been bining? could they have been bining?
Interro-negative form
Simple form
couldn't I bin? couldn't you bin? couldn't she bin? couldn't we bin? couldn't you bin? couldn't they bin?
V-ing form
couldn't I be bining? couldn't you be bining? couldn't she be bining? couldn't we be bining? couldn't you be bining? couldn't they be bining?
Perfect
couldn't I have bined? couldn't you have bined? couldn't she have bined? couldn't we have bined? couldn't you have bined? couldn't they have bined?
V-ing perfect
couldn't I have been bining? couldn't you have been bining? couldn't she have been bining? couldn't we have been bining? couldn't you have been bining? couldn't they have been bining?