I could collide you could collide she could collide we could collide you could collide they could collide
V-ing form
I could be colliding you could be colliding she could be colliding we could be colliding you could be colliding they could be colliding
Perfect
I could have collided you could have collided she 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 she 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 she 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 she 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 she 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 she 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 she collide? could we collide? could you collide? could they collide?
V-ing form
could I be colliding? could you be colliding? could she be colliding? could we be colliding? could you be colliding? could they be colliding?
Perfect
could I have collided? could you have collided? could she 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 she 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 she 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 she 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 she 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 she have been colliding? couldn't we have been colliding? couldn't you have been colliding? couldn't they have been colliding?