may grub
Regular verb: grub - grubbed- grubbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may grub
you may grub
she may grub
we may grub
you may grub
they may grub 	I may be grubbing
you may be grubbing
she may be grubbing
we may be grubbing
you may be grubbing
they may be grubbing	I may have grubbed
you may have grubbed
she may have grubbed
we may have grubbed
you may have grubbed
they may have grubbed	I may have been grubbing
you may have been grubbing
she may have been grubbing
we may have been grubbing
you may have been grubbing
they may have been grubbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't grub
you mayn't grub
she mayn't grub
we mayn't grub
you mayn't grub
they mayn't grub 	I mayn't be grubbing
you mayn't be grubbing
she mayn't be grubbing
we mayn't be grubbing
you mayn't be grubbing
they mayn't be grubbing	I mayn't have grubbed
you mayn't have grubbed
she mayn't have grubbed
we mayn't have grubbed
you mayn't have grubbed
they mayn't have grubbed	I mayn't have been grubbing
you mayn't have been grubbing
she mayn't have been grubbing
we mayn't have been grubbing
you mayn't have been grubbing
they mayn't have been grubbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I grub?
may you grub?
may she grub?
may we grub?
may you grub?
may they grub? 	may I be grubbing?
may you be grubbing?
may she be grubbing?
may we be grubbing?
may you be grubbing?
may they be grubbing? 	may I have grubbed?
may you have grubbed?
may she have grubbed?
may we have grubbed?
may you have grubbed?
may they have grubbed? 	may I have been grubbing?
may you have been grubbing?
may she have been grubbing?
may we have been grubbing?
may you have been grubbing?
may they have been grubbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I grub?
mayn't you grub?
mayn't she grub?
mayn't we grub?
mayn't you grub?
mayn't they grub? 	mayn't I be grubbing?
mayn't you be grubbing?
mayn't she be grubbing?
mayn't we be grubbing?
mayn't you be grubbing?
mayn't they be grubbing? 	mayn't I have grubbed?
mayn't you have grubbed?
mayn't she have grubbed?
mayn't we have grubbed?
mayn't you have grubbed?
mayn't they have grubbed? 	mayn't I have been grubbing?
mayn't you have been grubbing?
mayn't she have been grubbing?
mayn't we have been grubbing?
mayn't you have been grubbing?
mayn't they have been grubbing?