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