I may substitute you may substitute he may substitute we may substitute you may substitute they may substitute
V-ing form
I may be substituting you may be substituting he may be substituting we may be substituting you may be substituting they may be substituting
Perfect
I may have substituted you may have substituted he may have substituted we may have substituted you may have substituted they may have substituted
V-ing perfect
I may have been substituting you may have been substituting he may have been substituting we may have been substituting you may have been substituting they may have been substituting
Negation
Simple form
I mayn't substitute you mayn't substitute he mayn't substitute we mayn't substitute you mayn't substitute they mayn't substitute
V-ing form
I mayn't be substituting you mayn't be substituting he mayn't be substituting we mayn't be substituting you mayn't be substituting they mayn't be substituting
Perfect
I mayn't have substituted you mayn't have substituted he mayn't have substituted we mayn't have substituted you mayn't have substituted they mayn't have substituted
V-ing perfect
I mayn't have been substituting you mayn't have been substituting he mayn't have been substituting we mayn't have been substituting you mayn't have been substituting they mayn't have been substituting
Interrogative form
Simple form
may I substitute? may you substitute? may he substitute? may we substitute? may you substitute? may they substitute?
V-ing form
may I be substituting? may you be substituting? may he be substituting? may we be substituting? may you be substituting? may they be substituting?
Perfect
may I have substituted? may you have substituted? may he have substituted? may we have substituted? may you have substituted? may they have substituted?
V-ing perfect
may I have been substituting? may you have been substituting? may he have been substituting? may we have been substituting? may you have been substituting? may they have been substituting?
Interro-negative form
Simple form
mayn't I substitute? mayn't you substitute? mayn't he substitute? mayn't we substitute? mayn't you substitute? mayn't they substitute?
V-ing form
mayn't I be substituting? mayn't you be substituting? mayn't he be substituting? mayn't we be substituting? mayn't you be substituting? mayn't they be substituting?
Perfect
mayn't I have substituted? mayn't you have substituted? mayn't he have substituted? mayn't we have substituted? mayn't you have substituted? mayn't they have substituted?
V-ing perfect
mayn't I have been substituting? mayn't you have been substituting? mayn't he have been substituting? mayn't we have been substituting? mayn't you have been substituting? mayn't they have been substituting?