must challenge
Verbo regular: challenge - challenged- challenged

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must challenge
you must challenge
he must challenge
we must challenge
you must challenge
they must challenge 	I must be challenging
you must be challenging
he must be challenging
we must be challenging
you must be challenging
they must be challenging	I must have challenged
you must have challenged
he must have challenged
we must have challenged
you must have challenged
they must have challenged	I must have been challenging
you must have been challenging
he must have been challenging
we must have been challenging
you must have been challenging
they must have been challenging	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not challenge
you must not challenge
he must not challenge
we must not challenge
you must not challenge
they must not challenge 	I must not be challenging
you must not be challenging
he must not be challenging
we must not be challenging
you must not be challenging
they must not be challenging	I must not have challenged
you must not have challenged
he must not have challenged
we must not have challenged
you must not have challenged
they must not have challenged	I must not have been challenging
you must not have been challenging
he must not have been challenging
we must not have been challenging
you must not have been challenging
they must not have been challenging	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I challenge?
must you challenge?
must he challenge?
must we challenge?
must you challenge?
must they challenge? 	must I be challenging?
must you be challenging?
must he be challenging?
must we be challenging?
must you be challenging?
must they be challenging? 	must I have challenged?
must you have challenged?
must he have challenged?
must we have challenged?
must you have challenged?
must they have challenged? 	must I have been challenging?
must you have been challenging?
must he have been challenging?
must we have been challenging?
must you have been challenging?
must they have been challenging? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not challenge?
must you not challenge?
must he not challenge?
must we not challenge?
must you not challenge?
must they not challenge? 	must I not be challenging?
must you not be challenging?
must he not be challenging?
must we not be challenging?
must you not be challenging?
must they not be challenging? 	must I not have challenged?
must you not have challenged?
must he not have challenged?
must we not have challenged?
must you not have challenged?
must they not have challenged? 	must I not have been challenging?
must you not have been challenging?
must he not have been challenging?
must we not have been challenging?
must you not have been challenging?
must they not have been challenging?