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