
Regular verb: commence - commenced - commenced
Simple form | V-ing form | 
| I may commence you may commence she may commence we may commence you may commence they may commence  | I may be commencing you may be commencing she may be commencing we may be commencing you may be commencing they may be commencing  | 
Perfect | V-ing perfect | 
| I may have commenced you may have commenced she may have commenced we may have commenced you may have commenced they may have commenced  | I may have been commencing you may have been commencing she may have been commencing we may have been commencing you may have been commencing they may have been commencing  | 
Simple form | V-ing form | 
| I mayn't commence you mayn't commence she mayn't commence we mayn't commence you mayn't commence they mayn't commence  | I mayn't be commencing you mayn't be commencing she mayn't be commencing we mayn't be commencing you mayn't be commencing they mayn't be commencing  | 
Perfect | V-ing perfect | 
| I mayn't have commenced you mayn't have commenced she mayn't have commenced we mayn't have commenced you mayn't have commenced they mayn't have commenced  | I mayn't have been commencing you mayn't have been commencing she mayn't have been commencing we mayn't have been commencing you mayn't have been commencing they mayn't have been commencing  | 
Simple form | V-ing form | 
| may I commence? may you commence? may she commence? may we commence? may you commence? may they commence?  | may I be commencing? may you be commencing? may she be commencing? may we be commencing? may you be commencing? may they be commencing?  | 
Perfect | V-ing perfect | 
| may I have commenced? may you have commenced? may she have commenced? may we have commenced? may you have commenced? may they have commenced?  | may I have been commencing? may you have been commencing? may she have been commencing? may we have been commencing? may you have been commencing? may they have been commencing?  | 
Simple form | V-ing form | 
| mayn't I commence? mayn't you commence? mayn't she commence? mayn't we commence? mayn't you commence? mayn't they commence?  | mayn't I be commencing? mayn't you be commencing? mayn't she be commencing? mayn't we be commencing? mayn't you be commencing? mayn't they be commencing?  | 
Perfect | V-ing perfect | 
| mayn't I have commenced? mayn't you have commenced? mayn't she have commenced? mayn't we have commenced? mayn't you have commenced? mayn't they have commenced?  | mayn't I have been commencing? mayn't you have been commencing? mayn't she have been commencing? mayn't we have been commencing? mayn't you have been commencing? mayn't they have been commencing?  |