can jackknife
Verbo regular: jackknife - jackknifed- jackknifed

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

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

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

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