I may investigate you may investigate he may investigate we may investigate you may investigate they may investigate
V-ing form
I may be investigating you may be investigating he may be investigating we may be investigating you may be investigating they may be investigating
Perfect
I may have investigated you may have investigated he 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 he 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 he 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 he 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 he 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 he 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 he investigate? may we investigate? may you investigate? may they investigate?
V-ing form
may I be investigating? may you be investigating? may he be investigating? may we be investigating? may you be investigating? may they be investigating?
Perfect
may I have investigated? may you have investigated? may he 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 he 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 he 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 he 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 he 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 he have been investigating? mayn't we have been investigating? mayn't you have been investigating? mayn't they have been investigating?