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