may quack
Regular verb: quack - quacked- quacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may quack
you may quack
she may quack
we may quack
you may quack
they may quack 	I may be quacking
you may be quacking
she may be quacking
we may be quacking
you may be quacking
they may be quacking	I may have quacked
you may have quacked
she may have quacked
we may have quacked
you may have quacked
they may have quacked	I may have been quacking
you may have been quacking
she may have been quacking
we may have been quacking
you may have been quacking
they may have been quacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't quack
you mayn't quack
she mayn't quack
we mayn't quack
you mayn't quack
they mayn't quack 	I mayn't be quacking
you mayn't be quacking
she mayn't be quacking
we mayn't be quacking
you mayn't be quacking
they mayn't be quacking	I mayn't have quacked
you mayn't have quacked
she mayn't have quacked
we mayn't have quacked
you mayn't have quacked
they mayn't have quacked	I mayn't have been quacking
you mayn't have been quacking
she mayn't have been quacking
we mayn't have been quacking
you mayn't have been quacking
they mayn't have been quacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I quack?
may you quack?
may she quack?
may we quack?
may you quack?
may they quack? 	may I be quacking?
may you be quacking?
may she be quacking?
may we be quacking?
may you be quacking?
may they be quacking? 	may I have quacked?
may you have quacked?
may she have quacked?
may we have quacked?
may you have quacked?
may they have quacked? 	may I have been quacking?
may you have been quacking?
may she have been quacking?
may we have been quacking?
may you have been quacking?
may they have been quacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I quack?
mayn't you quack?
mayn't she quack?
mayn't we quack?
mayn't you quack?
mayn't they quack? 	mayn't I be quacking?
mayn't you be quacking?
mayn't she be quacking?
mayn't we be quacking?
mayn't you be quacking?
mayn't they be quacking? 	mayn't I have quacked?
mayn't you have quacked?
mayn't she have quacked?
mayn't we have quacked?
mayn't you have quacked?
mayn't they have quacked? 	mayn't I have been quacking?
mayn't you have been quacking?
mayn't she have been quacking?
mayn't we have been quacking?
mayn't you have been quacking?
mayn't they have been quacking?