should darken
Regular verb: darken - darkened- darkened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should darken
you should darken
she should darken
we should darken
you should darken
they should darken 	I should be darkening
you should be darkening
she should be darkening
we should be darkening
you should be darkening
they should be darkening	I should have darkened
you should have darkened
she should have darkened
we should have darkened
you should have darkened
they should have darkened	I should have been darkening
you should have been darkening
she should have been darkening
we should have been darkening
you should have been darkening
they should have been darkening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not darken
you should not darken
she should not darken
we should not darken
you should not darken
they should not darken 	I should not be darkening
you should not be darkening
she should not be darkening
we should not be darkening
you should not be darkening
they should not be darkening	I should not have darkened
you should not have darkened
she should not have darkened
we should not have darkened
you should not have darkened
they should not have darkened	I should not have been darkening
you should not have been darkening
she should not have been darkening
we should not have been darkening
you should not have been darkening
they should not have been darkening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I darken?
should you darken?
should she darken?
should we darken?
should you darken?
should they darken? 	should I be darkening?
should you be darkening?
should she be darkening?
should we be darkening?
should you be darkening?
should they be darkening? 	should I have darkened?
should you have darkened?
should she have darkened?
should we have darkened?
should you have darkened?
should they have darkened? 	should I have been darkening?
should you have been darkening?
should she have been darkening?
should we have been darkening?
should you have been darkening?
should they have been darkening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not darken?
should you not darken?
should she not darken?
should we not darken?
should you not darken?
should they not darken? 	should I not be darkening?
should you not be darkening?
should she not be darkening?
should we not be darkening?
should you not be darkening?
should they not be darkening? 	should I not have darkened?
should you not have darkened?
should she not have darkened?
should we not have darkened?
should you not have darkened?
should they not have darkened? 	should I not have been darkening?
should you not have been darkening?
should she not have been darkening?
should we not have been darkening?
should you not have been darkening?
should they not have been darkening?