could overtighten
Regular verb: overtighten - overtightened- overtightened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could overtighten
you could overtighten
he could overtighten
we could overtighten
you could overtighten
they could overtighten 	I could be overtightening
you could be overtightening
he could be overtightening
we could be overtightening
you could be overtightening
they could be overtightening	I could have overtightened
you could have overtightened
he could have overtightened
we could have overtightened
you could have overtightened
they could have overtightened	I could have been overtightening
you could have been overtightening
he could have been overtightening
we could have been overtightening
you could have been overtightening
they could have been overtightening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not overtighten
you could not overtighten
he could not overtighten
we could not overtighten
you could not overtighten
they could not overtighten 	I could not be overtightening
you could not be overtightening
he could not be overtightening
we could not be overtightening
you could not be overtightening
they could not be overtightening	I could not have overtightened
you could not have overtightened
he could not have overtightened
we could not have overtightened
you could not have overtightened
they could not have overtightened	I could not have been overtightening
you could not have been overtightening
he could not have been overtightening
we could not have been overtightening
you could not have been overtightening
they could not have been overtightening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I overtighten?
could you overtighten?
could he overtighten?
could we overtighten?
could you overtighten?
could they overtighten? 	could I be overtightening?
could you be overtightening?
could he be overtightening?
could we be overtightening?
could you be overtightening?
could they be overtightening? 	could I have overtightened?
could you have overtightened?
could he have overtightened?
could we have overtightened?
could you have overtightened?
could they have overtightened? 	could I have been overtightening?
could you have been overtightening?
could he have been overtightening?
could we have been overtightening?
could you have been overtightening?
could they have been overtightening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not overtighten?
could you not overtighten?
could he not overtighten?
could we not overtighten?
could you not overtighten?
could they not overtighten? 	could I not be overtightening?
could you not be overtightening?
could he not be overtightening?
could we not be overtightening?
could you not be overtightening?
could they not be overtightening? 	could I not have overtightened?
could you not have overtightened?
could he not have overtightened?
could we not have overtightened?
could you not have overtightened?
could they not have overtightened? 	could I not have been overtightening?
could you not have been overtightening?
could he not have been overtightening?
could we not have been overtightening?
could you not have been overtightening?
could they not have been overtightening?