could unstick
Regular verb: unstick - unsticked- unsticked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could unstick
you could unstick
he could unstick
we could unstick
you could unstick
they could unstick 	I could be unsticking
you could be unsticking
he could be unsticking
we could be unsticking
you could be unsticking
they could be unsticking	I could have unsticked
you could have unsticked
he could have unsticked
we could have unsticked
you could have unsticked
they could have unsticked	I could have been unsticking
you could have been unsticking
he could have been unsticking
we could have been unsticking
you could have been unsticking
they could have been unsticking	

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

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