may back
Regular verb: back - backed- backed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may back
you may back
she may back
we may back
you may back
they may back 	I may be backing
you may be backing
she may be backing
we may be backing
you may be backing
they may be backing	I may have backed
you may have backed
she may have backed
we may have backed
you may have backed
they may have backed	I may have been backing
you may have been backing
she may have been backing
we may have been backing
you may have been backing
they may have been backing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't back
you mayn't back
she mayn't back
we mayn't back
you mayn't back
they mayn't back 	I mayn't be backing
you mayn't be backing
she mayn't be backing
we mayn't be backing
you mayn't be backing
they mayn't be backing	I mayn't have backed
you mayn't have backed
she mayn't have backed
we mayn't have backed
you mayn't have backed
they mayn't have backed	I mayn't have been backing
you mayn't have been backing
she mayn't have been backing
we mayn't have been backing
you mayn't have been backing
they mayn't have been backing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I back?
may you back?
may she back?
may we back?
may you back?
may they back? 	may I be backing?
may you be backing?
may she be backing?
may we be backing?
may you be backing?
may they be backing? 	may I have backed?
may you have backed?
may she have backed?
may we have backed?
may you have backed?
may they have backed? 	may I have been backing?
may you have been backing?
may she have been backing?
may we have been backing?
may you have been backing?
may they have been backing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I back?
mayn't you back?
mayn't she back?
mayn't we back?
mayn't you back?
mayn't they back? 	mayn't I be backing?
mayn't you be backing?
mayn't she be backing?
mayn't we be backing?
mayn't you be backing?
mayn't they be backing? 	mayn't I have backed?
mayn't you have backed?
mayn't she have backed?
mayn't we have backed?
mayn't you have backed?
mayn't they have backed? 	mayn't I have been backing?
mayn't you have been backing?
mayn't she have been backing?
mayn't we have been backing?
mayn't you have been backing?
mayn't they have been backing?