may challenge
Regular verb: challenge - challenged- challenged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may challenge
you may challenge
she may challenge
we may challenge
you may challenge
they may challenge 	I may be challenging
you may be challenging
she may be challenging
we may be challenging
you may be challenging
they may be challenging	I may have challenged
you may have challenged
she may have challenged
we may have challenged
you may have challenged
they may have challenged	I may have been challenging
you may have been challenging
she may have been challenging
we may have been challenging
you may have been challenging
they may have been challenging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't challenge
you mayn't challenge
she mayn't challenge
we mayn't challenge
you mayn't challenge
they mayn't challenge 	I mayn't be challenging
you mayn't be challenging
she mayn't be challenging
we mayn't be challenging
you mayn't be challenging
they mayn't be challenging	I mayn't have challenged
you mayn't have challenged
she mayn't have challenged
we mayn't have challenged
you mayn't have challenged
they mayn't have challenged	I mayn't have been challenging
you mayn't have been challenging
she mayn't have been challenging
we mayn't have been challenging
you mayn't have been challenging
they mayn't have been challenging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I challenge?
may you challenge?
may she challenge?
may we challenge?
may you challenge?
may they challenge? 	may I be challenging?
may you be challenging?
may she be challenging?
may we be challenging?
may you be challenging?
may they be challenging? 	may I have challenged?
may you have challenged?
may she have challenged?
may we have challenged?
may you have challenged?
may they have challenged? 	may I have been challenging?
may you have been challenging?
may she have been challenging?
may we have been challenging?
may you have been challenging?
may they have been challenging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I challenge?
mayn't you challenge?
mayn't she challenge?
mayn't we challenge?
mayn't you challenge?
mayn't they challenge? 	mayn't I be challenging?
mayn't you be challenging?
mayn't she be challenging?
mayn't we be challenging?
mayn't you be challenging?
mayn't they be challenging? 	mayn't I have challenged?
mayn't you have challenged?
mayn't she have challenged?
mayn't we have challenged?
mayn't you have challenged?
mayn't they have challenged? 	mayn't I have been challenging?
mayn't you have been challenging?
mayn't she have been challenging?
mayn't we have been challenging?
mayn't you have been challenging?
mayn't they have been challenging?