English verb conjugation
MAY STACK

Regular verb: stack - stacked - stacked

Affirmation

Simple form	V-ing form
I may stack you may stack he may stack we may stack you may stack they may stack	I may be stacking you may be stacking he may be stacking we may be stacking you may be stacking they may be stacking
Perfect	V-ing perfect
I may have stacked you may have stacked he may have stacked we may have stacked you may have stacked they may have stacked	I may have been stacking you may have been stacking he may have been stacking we may have been stacking you may have been stacking they may have been stacking

Negation

Simple form	V-ing form
I mayn't stack you mayn't stack he mayn't stack we mayn't stack you mayn't stack they mayn't stack	I mayn't be stacking you mayn't be stacking he mayn't be stacking we mayn't be stacking you mayn't be stacking they mayn't be stacking
Perfect	V-ing perfect
I mayn't have stacked you mayn't have stacked he mayn't have stacked we mayn't have stacked you mayn't have stacked they mayn't have stacked	I mayn't have been stacking you mayn't have been stacking he mayn't have been stacking we mayn't have been stacking you mayn't have been stacking they mayn't have been stacking

Interrogative form

Simple form	V-ing form
may I stack? may you stack? may he stack? may we stack? may you stack? may they stack?	may I be stacking? may you be stacking? may he be stacking? may we be stacking? may you be stacking? may they be stacking?
Perfect	V-ing perfect
may I have stacked? may you have stacked? may he have stacked? may we have stacked? may you have stacked? may they have stacked?	may I have been stacking? may you have been stacking? may he have been stacking? may we have been stacking? may you have been stacking? may they have been stacking?

Interro-negative form

Simple form	V-ing form
mayn't I stack? mayn't you stack? mayn't he stack? mayn't we stack? mayn't you stack? mayn't they stack?	mayn't I be stacking? mayn't you be stacking? mayn't he be stacking? mayn't we be stacking? mayn't you be stacking? mayn't they be stacking?
Perfect	V-ing perfect
mayn't I have stacked? mayn't you have stacked? mayn't he have stacked? mayn't we have stacked? mayn't you have stacked? mayn't they have stacked?	mayn't I have been stacking? mayn't you have been stacking? mayn't he have been stacking? mayn't we have been stacking? mayn't you have been stacking? mayn't they have been stacking?