English verb conjugation
MUST INTERVENE

Regular verb: intervene - intervened - intervened

Affirmation

Simple form	V-ing form
I must intervene you must intervene she must intervene we must intervene you must intervene they must intervene	I must be intervening you must be intervening she must be intervening we must be intervening you must be intervening they must be intervening
Perfect	V-ing perfect
I must have intervened you must have intervened she must have intervened we must have intervened you must have intervened they must have intervened	I must have been intervening you must have been intervening she must have been intervening we must have been intervening you must have been intervening they must have been intervening

Negation

Simple form	V-ing form
I mustn't intervene you mustn't intervene she mustn't intervene we mustn't intervene you mustn't intervene they mustn't intervene	I mustn't be intervening you mustn't be intervening she mustn't be intervening we mustn't be intervening you mustn't be intervening they mustn't be intervening
Perfect	V-ing perfect
I mustn't have intervened you mustn't have intervened she mustn't have intervened we mustn't have intervened you mustn't have intervened they mustn't have intervened	I mustn't have been intervening you mustn't have been intervening she mustn't have been intervening we mustn't have been intervening you mustn't have been intervening they mustn't have been intervening

Interrogative form

Simple form	V-ing form
must I intervene? must you intervene? must she intervene? must we intervene? must you intervene? must they intervene?	must I be intervening? must you be intervening? must she be intervening? must we be intervening? must you be intervening? must they be intervening?
Perfect	V-ing perfect
must I have intervened? must you have intervened? must she have intervened? must we have intervened? must you have intervened? must they have intervened?	must I have been intervening? must you have been intervening? must she have been intervening? must we have been intervening? must you have been intervening? must they have been intervening?

Interro-negative form

Simple form	V-ing form
mustn't I intervene? mustn't you intervene? mustn't she intervene? mustn't we intervene? mustn't you intervene? mustn't they intervene?	mustn't I be intervening? mustn't you be intervening? mustn't she be intervening? mustn't we be intervening? mustn't you be intervening? mustn't they be intervening?
Perfect	V-ing perfect
mustn't I have intervened? mustn't you have intervened? mustn't she have intervened? mustn't we have intervened? mustn't you have intervened? mustn't they have intervened?	mustn't I have been intervening? mustn't you have been intervening? mustn't she have been intervening? mustn't we have been intervening? mustn't you have been intervening? mustn't they have been intervening?