could fasten
Verbo regular: fasten - fastened- fastened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could fasten
you could fasten
he could fasten
we could fasten
you could fasten
they could fasten 	I could be fastening
you could be fastening
he could be fastening
we could be fastening
you could be fastening
they could be fastening	I could have fastened
you could have fastened
he could have fastened
we could have fastened
you could have fastened
they could have fastened	I could have been fastening
you could have been fastening
he could have been fastening
we could have been fastening
you could have been fastening
they could have been fastening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't fasten
you couldn't fasten
he couldn't fasten
we couldn't fasten
you couldn't fasten
they couldn't fasten 	I couldn't be fastening
you couldn't be fastening
he couldn't be fastening
we couldn't be fastening
you couldn't be fastening
they couldn't be fastening	I couldn't have fastened
you couldn't have fastened
he couldn't have fastened
we couldn't have fastened
you couldn't have fastened
they couldn't have fastened	I couldn't have been fastening
you couldn't have been fastening
he couldn't have been fastening
we couldn't have been fastening
you couldn't have been fastening
they couldn't have been fastening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I fasten?
could you fasten?
could he fasten?
could we fasten?
could you fasten?
could they fasten? 	could I be fastening?
could you be fastening?
could he be fastening?
could we be fastening?
could you be fastening?
could they be fastening? 	could I have fastened?
could you have fastened?
could he have fastened?
could we have fastened?
could you have fastened?
could they have fastened? 	could I have been fastening?
could you have been fastening?
could he have been fastening?
could we have been fastening?
could you have been fastening?
could they have been fastening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I fasten?
couldn't you fasten?
couldn't he fasten?
couldn't we fasten?
couldn't you fasten?
couldn't they fasten? 	couldn't I be fastening?
couldn't you be fastening?
couldn't he be fastening?
couldn't we be fastening?
couldn't you be fastening?
couldn't they be fastening? 	couldn't I have fastened?
couldn't you have fastened?
couldn't he have fastened?
couldn't we have fastened?
couldn't you have fastened?
couldn't they have fastened? 	couldn't I have been fastening?
couldn't you have been fastening?
couldn't he have been fastening?
couldn't we have been fastening?
couldn't you have been fastening?
couldn't they have been fastening?