I may investigate you may investigate she may investigate we may investigate you may investigate they may investigate
V-ing form
I may be investigating you may be investigating she may be investigating we may be investigating you may be investigating they may be investigating
Perfect
I may have investigated you may have investigated she may have investigated we may have investigated you may have investigated they may have investigated
V-ing perfect
I may have been investigating you may have been investigating she may have been investigating we may have been investigating you may have been investigating they may have been investigating
Negation
Simple form
I mayn't investigate you mayn't investigate she mayn't investigate we mayn't investigate you mayn't investigate they mayn't investigate
V-ing form
I mayn't be investigating you mayn't be investigating she mayn't be investigating we mayn't be investigating you mayn't be investigating they mayn't be investigating
Perfect
I mayn't have investigated you mayn't have investigated she mayn't have investigated we mayn't have investigated you mayn't have investigated they mayn't have investigated
V-ing perfect
I mayn't have been investigating you mayn't have been investigating she mayn't have been investigating we mayn't have been investigating you mayn't have been investigating they mayn't have been investigating
Interrogative form
Simple form
may I investigate? may you investigate? may she investigate? may we investigate? may you investigate? may they investigate?
V-ing form
may I be investigating? may you be investigating? may she be investigating? may we be investigating? may you be investigating? may they be investigating?
Perfect
may I have investigated? may you have investigated? may she have investigated? may we have investigated? may you have investigated? may they have investigated?
V-ing perfect
may I have been investigating? may you have been investigating? may she have been investigating? may we have been investigating? may you have been investigating? may they have been investigating?
Interro-negative form
Simple form
mayn't I investigate? mayn't you investigate? mayn't she investigate? mayn't we investigate? mayn't you investigate? mayn't they investigate?
V-ing form
mayn't I be investigating? mayn't you be investigating? mayn't she be investigating? mayn't we be investigating? mayn't you be investigating? mayn't they be investigating?
Perfect
mayn't I have investigated? mayn't you have investigated? mayn't she have investigated? mayn't we have investigated? mayn't you have investigated? mayn't they have investigated?
V-ing perfect
mayn't I have been investigating? mayn't you have been investigating? mayn't she have been investigating? mayn't we have been investigating? mayn't you have been investigating? mayn't they have been investigating?