English verb conjugation
MUST INTERVENE

Regular verb: intervene - intervened - intervened

Affirmation

Simple form	V-ing form
I must intervene you must intervene he must intervene we must intervene you must intervene they must intervene	I must be intervening you must be intervening he 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 he 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 he 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 he 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 he 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 he 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 he 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 he intervene? must we intervene? must you intervene? must they intervene?	must I be intervening? must you be intervening? must he 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 he 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 he 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 he 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 he 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 he 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 he have been intervening? mustn't we have been intervening? mustn't you have been intervening? mustn't they have been intervening?