I could coast you could coast she could coast we could coast you could coast they could coast
V-ing form
I could be coasting you could be coasting she could be coasting we could be coasting you could be coasting they could be coasting
Perfect
I could have coasted you could have coasted she could have coasted we could have coasted you could have coasted they could have coasted
V-ing perfect
I could have been coasting you could have been coasting she could have been coasting we could have been coasting you could have been coasting they could have been coasting
Negation
Simple form
I could not coast you could not coast she could not coast we could not coast you could not coast they could not coast
V-ing form
I could not be coasting you could not be coasting she could not be coasting we could not be coasting you could not be coasting they could not be coasting
Perfect
I could not have coasted you could not have coasted she could not have coasted we could not have coasted you could not have coasted they could not have coasted
V-ing perfect
I could not have been coasting you could not have been coasting she could not have been coasting we could not have been coasting you could not have been coasting they could not have been coasting
Interrogative form
Simple form
could I coast? could you coast? could she coast? could we coast? could you coast? could they coast?
V-ing form
could I be coasting? could you be coasting? could she be coasting? could we be coasting? could you be coasting? could they be coasting?
Perfect
could I have coasted? could you have coasted? could she have coasted? could we have coasted? could you have coasted? could they have coasted?
V-ing perfect
could I have been coasting? could you have been coasting? could she have been coasting? could we have been coasting? could you have been coasting? could they have been coasting?
Interro-negative form
Simple form
could I not coast? could you not coast? could she not coast? could we not coast? could you not coast? could they not coast?
V-ing form
could I not be coasting? could you not be coasting? could she not be coasting? could we not be coasting? could you not be coasting? could they not be coasting?
Perfect
could I not have coasted? could you not have coasted? could she not have coasted? could we not have coasted? could you not have coasted? could they not have coasted?
V-ing perfect
could I not have been coasting? could you not have been coasting? could she not have been coasting? could we not have been coasting? could you not have been coasting? could they not have been coasting?