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