could tighten
Verbo regolare: tighten - tightened- tightened

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could tighten
you could tighten
he could tighten
we could tighten
you could tighten
they could tighten 	I could be tightening
you could be tightening
he could be tightening
we could be tightening
you could be tightening
they could be tightening	I could have tightened
you could have tightened
he could have tightened
we could have tightened
you could have tightened
they could have tightened	I could have been tightening
you could have been tightening
he could have been tightening
we could have been tightening
you could have been tightening
they could have been tightening	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could not tighten
you could not tighten
he could not tighten
we could not tighten
you could not tighten
they could not tighten 	I could not be tightening
you could not be tightening
he could not be tightening
we could not be tightening
you could not be tightening
they could not be tightening	I could not have tightened
you could not have tightened
he could not have tightened
we could not have tightened
you could not have tightened
they could not have tightened	I could not have been tightening
you could not have been tightening
he could not have been tightening
we could not have been tightening
you could not have been tightening
they could not have been tightening	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I tighten?
could you tighten?
could he tighten?
could we tighten?
could you tighten?
could they tighten? 	could I be tightening?
could you be tightening?
could he be tightening?
could we be tightening?
could you be tightening?
could they be tightening? 	could I have tightened?
could you have tightened?
could he have tightened?
could we have tightened?
could you have tightened?
could they have tightened? 	could I have been tightening?
could you have been tightening?
could he have been tightening?
could we have been tightening?
could you have been tightening?
could they have been tightening? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I not tighten?
could you not tighten?
could he not tighten?
could we not tighten?
could you not tighten?
could they not tighten? 	could I not be tightening?
could you not be tightening?
could he not be tightening?
could we not be tightening?
could you not be tightening?
could they not be tightening? 	could I not have tightened?
could you not have tightened?
could he not have tightened?
could we not have tightened?
could you not have tightened?
could they not have tightened? 	could I not have been tightening?
could you not have been tightening?
could he not have been tightening?
could we not have been tightening?
could you not have been tightening?
could they not have been tightening?