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