may rub
Regular verb: rub - rubbed- rubbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may rub
you may rub
she may rub
we may rub
you may rub
they may rub 	I may be rubbing
you may be rubbing
she may be rubbing
we may be rubbing
you may be rubbing
they may be rubbing	I may have rubbed
you may have rubbed
she may have rubbed
we may have rubbed
you may have rubbed
they may have rubbed	I may have been rubbing
you may have been rubbing
she may have been rubbing
we may have been rubbing
you may have been rubbing
they may have been rubbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't rub
you mayn't rub
she mayn't rub
we mayn't rub
you mayn't rub
they mayn't rub 	I mayn't be rubbing
you mayn't be rubbing
she mayn't be rubbing
we mayn't be rubbing
you mayn't be rubbing
they mayn't be rubbing	I mayn't have rubbed
you mayn't have rubbed
she mayn't have rubbed
we mayn't have rubbed
you mayn't have rubbed
they mayn't have rubbed	I mayn't have been rubbing
you mayn't have been rubbing
she mayn't have been rubbing
we mayn't have been rubbing
you mayn't have been rubbing
they mayn't have been rubbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I rub?
may you rub?
may she rub?
may we rub?
may you rub?
may they rub? 	may I be rubbing?
may you be rubbing?
may she be rubbing?
may we be rubbing?
may you be rubbing?
may they be rubbing? 	may I have rubbed?
may you have rubbed?
may she have rubbed?
may we have rubbed?
may you have rubbed?
may they have rubbed? 	may I have been rubbing?
may you have been rubbing?
may she have been rubbing?
may we have been rubbing?
may you have been rubbing?
may they have been rubbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I rub?
mayn't you rub?
mayn't she rub?
mayn't we rub?
mayn't you rub?
mayn't they rub? 	mayn't I be rubbing?
mayn't you be rubbing?
mayn't she be rubbing?
mayn't we be rubbing?
mayn't you be rubbing?
mayn't they be rubbing? 	mayn't I have rubbed?
mayn't you have rubbed?
mayn't she have rubbed?
mayn't we have rubbed?
mayn't you have rubbed?
mayn't they have rubbed? 	mayn't I have been rubbing?
mayn't you have been rubbing?
mayn't she have been rubbing?
mayn't we have been rubbing?
mayn't you have been rubbing?
mayn't they have been rubbing?