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