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