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