ought to darken
Regular verb: darken - darkened- darkened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to darken
you ought to darken
he ought to darken
we ought to darken
you ought to darken
they ought to darken 	I ought to be darkening
you ought to be darkening
he ought to be darkening
we ought to be darkening
you ought to be darkening
they ought to be darkening	I ought to have darkened
you ought to have darkened
he ought to have darkened
we ought to have darkened
you ought to have darkened
they ought to have darkened	I ought to have been darkening
you ought to have been darkening
he ought to have been darkening
we ought to have been darkening
you ought to have been darkening
they ought to have been darkening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I oughtn't to darken
you oughtn't to darken
he oughtn't to darken
we oughtn't to darken
you oughtn't to darken
they oughtn't to darken 	I oughtn't to be darkening
you oughtn't to be darkening
he oughtn't to be darkening
we oughtn't to be darkening
you oughtn't to be darkening
they oughtn't to be darkening	I oughtn't to have darkened
you oughtn't to have darkened
he oughtn't to have darkened
we oughtn't to have darkened
you oughtn't to have darkened
they oughtn't to have darkened	I oughtn't to have been darkening
you oughtn't to have been darkening
he oughtn't to have been darkening
we oughtn't to have been darkening
you oughtn't to have been darkening
they oughtn't to have been darkening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I darken?
ought to you darken?
ought to he darken?
ought to we darken?
ought to you darken?
ought to they darken? 	ought to I be darkening?
ought to you be darkening?
ought to he be darkening?
ought to we be darkening?
ought to you be darkening?
ought to they be darkening? 	ought to I have darkened?
ought to you have darkened?
ought to he have darkened?
ought to we have darkened?
ought to you have darkened?
ought to they have darkened? 	ought to I have been darkening?
ought to you have been darkening?
ought to he have been darkening?
ought to we have been darkening?
ought to you have been darkening?
ought to they have been darkening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
oughtn't I to darken?
oughtn't you to darken?
oughtn't he to darken?
oughtn't we to darken?
oughtn't you to darken?
oughtn't they to darken? 	oughtn't I to be darkening?
oughtn't you to be darkening?
oughtn't he to be darkening?
oughtn't we to be darkening?
oughtn't you to be darkening?
oughtn't they to be darkening? 	oughtn't I to have darkened?
oughtn't you to have darkened?
oughtn't he to have darkened?
oughtn't we to have darkened?
oughtn't you to have darkened?
oughtn't they to have darkened? 	oughtn't I to have been darkening?
oughtn't you to have been darkening?
oughtn't he to have been darkening?
oughtn't we to have been darkening?
oughtn't you to have been darkening?
oughtn't they to have been darkening?