must jackknife
Verbo regular: jackknife - jackknifed- jackknifed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must jackknife
you must jackknife
he must jackknife
we must jackknife
you must jackknife
they must jackknife 	I must be jackknifing
you must be jackknifing
he must be jackknifing
we must be jackknifing
you must be jackknifing
they must be jackknifing	I must have jackknifed
you must have jackknifed
he must have jackknifed
we must have jackknifed
you must have jackknifed
they must have jackknifed	I must have been jackknifing
you must have been jackknifing
he must have been jackknifing
we must have been jackknifing
you must have been jackknifing
they must have been jackknifing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't jackknife
you mustn't jackknife
he mustn't jackknife
we mustn't jackknife
you mustn't jackknife
they mustn't jackknife 	I mustn't be jackknifing
you mustn't be jackknifing
he mustn't be jackknifing
we mustn't be jackknifing
you mustn't be jackknifing
they mustn't be jackknifing	I mustn't have jackknifed
you mustn't have jackknifed
he mustn't have jackknifed
we mustn't have jackknifed
you mustn't have jackknifed
they mustn't have jackknifed	I mustn't have been jackknifing
you mustn't have been jackknifing
he mustn't have been jackknifing
we mustn't have been jackknifing
you mustn't have been jackknifing
they mustn't have been jackknifing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I jackknife?
must you jackknife?
must he jackknife?
must we jackknife?
must you jackknife?
must they jackknife? 	must I be jackknifing?
must you be jackknifing?
must he be jackknifing?
must we be jackknifing?
must you be jackknifing?
must they be jackknifing? 	must I have jackknifed?
must you have jackknifed?
must he have jackknifed?
must we have jackknifed?
must you have jackknifed?
must they have jackknifed? 	must I have been jackknifing?
must you have been jackknifing?
must he have been jackknifing?
must we have been jackknifing?
must you have been jackknifing?
must they have been jackknifing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I jackknife?
mustn't you jackknife?
mustn't he jackknife?
mustn't we jackknife?
mustn't you jackknife?
mustn't they jackknife? 	mustn't I be jackknifing?
mustn't you be jackknifing?
mustn't he be jackknifing?
mustn't we be jackknifing?
mustn't you be jackknifing?
mustn't they be jackknifing? 	mustn't I have jackknifed?
mustn't you have jackknifed?
mustn't he have jackknifed?
mustn't we have jackknifed?
mustn't you have jackknifed?
mustn't they have jackknifed? 	mustn't I have been jackknifing?
mustn't you have been jackknifing?
mustn't he have been jackknifing?
mustn't we have been jackknifing?
mustn't you have been jackknifing?
mustn't they have been jackknifing?