should blacken
Regular verb: blacken - blackened- blackened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd blacken
you'd blacken
he'd blacken
we'd blacken
you'd blacken
they'd blacken 	I'd be blackening
you'd be blackening
he'd be blackening
we'd be blackening
you'd be blackening
they'd be blackening	I should've blackened
you should've blackened
he should've blackened
we should've blackened
you should've blackened
they should've blackened	I should've been blackening
you should've been blackening
he should've been blackening
we should've been blackening
you should've been blackening
they should've been blackening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't blacken
you shouldn't blacken
he shouldn't blacken
we shouldn't blacken
you shouldn't blacken
they shouldn't blacken 	I shouldn't be blackening
you shouldn't be blackening
he shouldn't be blackening
we shouldn't be blackening
you shouldn't be blackening
they shouldn't be blackening	I shouldn't have blackened
you shouldn't have blackened
he shouldn't have blackened
we shouldn't have blackened
you shouldn't have blackened
they shouldn't have blackened	I shouldn't have been blackening
you shouldn't have been blackening
he shouldn't have been blackening
we shouldn't have been blackening
you shouldn't have been blackening
they shouldn't have been blackening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I blacken?
should you blacken?
should he blacken?
should we blacken?
should you blacken?
should they blacken? 	should I be blackening?
should you be blackening?
should he be blackening?
should we be blackening?
should you be blackening?
should they be blackening? 	should I have blackened?
should you have blackened?
should he have blackened?
should we have blackened?
should you have blackened?
should they have blackened? 	should I have been blackening?
should you have been blackening?
should he have been blackening?
should we have been blackening?
should you have been blackening?
should they have been blackening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I blacken?
shouldn't you blacken?
shouldn't he blacken?
shouldn't we blacken?
shouldn't you blacken?
shouldn't they blacken? 	shouldn't I be blackening?
shouldn't you be blackening?
shouldn't he be blackening?
shouldn't we be blackening?
shouldn't you be blackening?
shouldn't they be blackening? 	shouldn't I have blackened?
shouldn't you have blackened?
shouldn't he have blackened?
shouldn't we have blackened?
shouldn't you have blackened?
shouldn't they have blackened? 	shouldn't I have been blackening?
shouldn't you have been blackening?
shouldn't he have been blackening?
shouldn't we have been blackening?
shouldn't you have been blackening?
shouldn't they have been blackening?