should fasten
Verbo regular: fasten - fastened- fastened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I'd fasten
you'd fasten
she'd fasten
we'd fasten
you'd fasten
they'd fasten 	I'd be fastening
you'd be fastening
she'd be fastening
we'd be fastening
you'd be fastening
they'd be fastening	I should've fastened
you should've fastened
she should've fastened
we should've fastened
you should've fastened
they should've fastened	I should've been fastening
you should've been fastening
she should've been fastening
we should've been fastening
you should've been fastening
they should've been fastening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I shouldn't fasten
you shouldn't fasten
she shouldn't fasten
we shouldn't fasten
you shouldn't fasten
they shouldn't fasten 	I shouldn't be fastening
you shouldn't be fastening
she shouldn't be fastening
we shouldn't be fastening
you shouldn't be fastening
they shouldn't be fastening	I shouldn't have fastened
you shouldn't have fastened
she shouldn't have fastened
we shouldn't have fastened
you shouldn't have fastened
they shouldn't have fastened	I shouldn't have been fastening
you shouldn't have been fastening
she shouldn't have been fastening
we shouldn't have been fastening
you shouldn't have been fastening
they shouldn't have been fastening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
should I fasten?
should you fasten?
should she fasten?
should we fasten?
should you fasten?
should they fasten? 	should I be fastening?
should you be fastening?
should she be fastening?
should we be fastening?
should you be fastening?
should they be fastening? 	should I have fastened?
should you have fastened?
should she have fastened?
should we have fastened?
should you have fastened?
should they have fastened? 	should I have been fastening?
should you have been fastening?
should she have been fastening?
should we have been fastening?
should you have been fastening?
should they have been fastening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
shouldn't I fasten?
shouldn't you fasten?
shouldn't she fasten?
shouldn't we fasten?
shouldn't you fasten?
shouldn't they fasten? 	shouldn't I be fastening?
shouldn't you be fastening?
shouldn't she be fastening?
shouldn't we be fastening?
shouldn't you be fastening?
shouldn't they be fastening? 	shouldn't I have fastened?
shouldn't you have fastened?
shouldn't she have fastened?
shouldn't we have fastened?
shouldn't you have fastened?
shouldn't they have fastened? 	shouldn't I have been fastening?
shouldn't you have been fastening?
shouldn't she have been fastening?
shouldn't we have been fastening?
shouldn't you have been fastening?
shouldn't they have been fastening?