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
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	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	

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

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

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