could unfasten
Verbo regular: unfasten - unfastened- unfastened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could unfasten
you could unfasten
she could unfasten
we could unfasten
you could unfasten
they could unfasten 	I could be unfastening
you could be unfastening
she could be unfastening
we could be unfastening
you could be unfastening
they could be unfastening	I could have unfastened
you could have unfastened
she could have unfastened
we could have unfastened
you could have unfastened
they could have unfastened	I could have been unfastening
you could have been unfastening
she could have been unfastening
we could have been unfastening
you could have been unfastening
they could have been unfastening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't unfasten
you couldn't unfasten
she couldn't unfasten
we couldn't unfasten
you couldn't unfasten
they couldn't unfasten 	I couldn't be unfastening
you couldn't be unfastening
she couldn't be unfastening
we couldn't be unfastening
you couldn't be unfastening
they couldn't be unfastening	I couldn't have unfastened
you couldn't have unfastened
she couldn't have unfastened
we couldn't have unfastened
you couldn't have unfastened
they couldn't have unfastened	I couldn't have been unfastening
you couldn't have been unfastening
she couldn't have been unfastening
we couldn't have been unfastening
you couldn't have been unfastening
they couldn't have been unfastening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I unfasten?
could you unfasten?
could she unfasten?
could we unfasten?
could you unfasten?
could they unfasten? 	could I be unfastening?
could you be unfastening?
could she be unfastening?
could we be unfastening?
could you be unfastening?
could they be unfastening? 	could I have unfastened?
could you have unfastened?
could she have unfastened?
could we have unfastened?
could you have unfastened?
could they have unfastened? 	could I have been unfastening?
could you have been unfastening?
could she have been unfastening?
could we have been unfastening?
could you have been unfastening?
could they have been unfastening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I unfasten?
couldn't you unfasten?
couldn't she unfasten?
couldn't we unfasten?
couldn't you unfasten?
couldn't they unfasten? 	couldn't I be unfastening?
couldn't you be unfastening?
couldn't she be unfastening?
couldn't we be unfastening?
couldn't you be unfastening?
couldn't they be unfastening? 	couldn't I have unfastened?
couldn't you have unfastened?
couldn't she have unfastened?
couldn't we have unfastened?
couldn't you have unfastened?
couldn't they have unfastened? 	couldn't I have been unfastening?
couldn't you have been unfastening?
couldn't she have been unfastening?
couldn't we have been unfastening?
couldn't you have been unfastening?
couldn't they have been unfastening?