English verb conjugation
MAY STACK

Regular verb: stack - stacked - stacked

Affirmation

Simple form	V-ing form
I may stack you may stack she may stack we may stack you may stack they may stack	I may be stacking you may be stacking she 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 she 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 she 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 she 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 she 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 she 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 she 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 she stack? may we stack? may you stack? may they stack?	may I be stacking? may you be stacking? may she 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 she 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 she 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 she 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 she 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 she 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 she have been stacking? mayn't we have been stacking? mayn't you have been stacking? mayn't they have been stacking?