ought to intervene
Regular verb: intervene - intervened- intervened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to intervene
you ought to intervene
he ought to intervene
we ought to intervene
you ought to intervene
they ought to intervene 	I ought to be intervening
you ought to be intervening
he ought to be intervening
we ought to be intervening
you ought to be intervening
they ought to be intervening	I ought to have intervened
you ought to have intervened
he ought to have intervened
we ought to have intervened
you ought to have intervened
they ought to have intervened	I ought to have been intervening
you ought to have been intervening
he ought to have been intervening
we ought to have been intervening
you ought to have been intervening
they ought to have been intervening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I oughtn't to intervene
you oughtn't to intervene
he oughtn't to intervene
we oughtn't to intervene
you oughtn't to intervene
they oughtn't to intervene 	I oughtn't to be intervening
you oughtn't to be intervening
he oughtn't to be intervening
we oughtn't to be intervening
you oughtn't to be intervening
they oughtn't to be intervening	I oughtn't to have intervened
you oughtn't to have intervened
he oughtn't to have intervened
we oughtn't to have intervened
you oughtn't to have intervened
they oughtn't to have intervened	I oughtn't to have been intervening
you oughtn't to have been intervening
he oughtn't to have been intervening
we oughtn't to have been intervening
you oughtn't to have been intervening
they oughtn't to have been intervening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I intervene?
ought to you intervene?
ought to he intervene?
ought to we intervene?
ought to you intervene?
ought to they intervene? 	ought to I be intervening?
ought to you be intervening?
ought to he be intervening?
ought to we be intervening?
ought to you be intervening?
ought to they be intervening? 	ought to I have intervened?
ought to you have intervened?
ought to he have intervened?
ought to we have intervened?
ought to you have intervened?
ought to they have intervened? 	ought to I have been intervening?
ought to you have been intervening?
ought to he have been intervening?
ought to we have been intervening?
ought to you have been intervening?
ought to they have been intervening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
oughtn't I to intervene?
oughtn't you to intervene?
oughtn't he to intervene?
oughtn't we to intervene?
oughtn't you to intervene?
oughtn't they to intervene? 	oughtn't I to be intervening?
oughtn't you to be intervening?
oughtn't he to be intervening?
oughtn't we to be intervening?
oughtn't you to be intervening?
oughtn't they to be intervening? 	oughtn't I to have intervened?
oughtn't you to have intervened?
oughtn't he to have intervened?
oughtn't we to have intervened?
oughtn't you to have intervened?
oughtn't they to have intervened? 	oughtn't I to have been intervening?
oughtn't you to have been intervening?
oughtn't he to have been intervening?
oughtn't we to have been intervening?
oughtn't you to have been intervening?
oughtn't they to have been intervening?