must intervene
Verbo regular: intervene - intervened- intervened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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	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	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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	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	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	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? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	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?