English verb conjugation
MAY SUM

Regular verb: sum - summed - summed

Affirmation

Simple form	V-ing form
I may sum you may sum he may sum we may sum you may sum they may sum	I may be summing you may be summing he may be summing we may be summing you may be summing they may be summing
Perfect	V-ing perfect
I may have summed you may have summed he may have summed we may have summed you may have summed they may have summed	I may have been summing you may have been summing he may have been summing we may have been summing you may have been summing they may have been summing

Negation

Simple form	V-ing form
I mayn't sum you mayn't sum he mayn't sum we mayn't sum you mayn't sum they mayn't sum	I mayn't be summing you mayn't be summing he mayn't be summing we mayn't be summing you mayn't be summing they mayn't be summing
Perfect	V-ing perfect
I mayn't have summed you mayn't have summed he mayn't have summed we mayn't have summed you mayn't have summed they mayn't have summed	I mayn't have been summing you mayn't have been summing he mayn't have been summing we mayn't have been summing you mayn't have been summing they mayn't have been summing

Interrogative form

Simple form	V-ing form
may I sum? may you sum? may he sum? may we sum? may you sum? may they sum?	may I be summing? may you be summing? may he be summing? may we be summing? may you be summing? may they be summing?
Perfect	V-ing perfect
may I have summed? may you have summed? may he have summed? may we have summed? may you have summed? may they have summed?	may I have been summing? may you have been summing? may he have been summing? may we have been summing? may you have been summing? may they have been summing?

Interro-negative form

Simple form	V-ing form
mayn't I sum? mayn't you sum? mayn't he sum? mayn't we sum? mayn't you sum? mayn't they sum?	mayn't I be summing? mayn't you be summing? mayn't he be summing? mayn't we be summing? mayn't you be summing? mayn't they be summing?
Perfect	V-ing perfect
mayn't I have summed? mayn't you have summed? mayn't he have summed? mayn't we have summed? mayn't you have summed? mayn't they have summed?	mayn't I have been summing? mayn't you have been summing? mayn't he have been summing? mayn't we have been summing? mayn't you have been summing? mayn't they have been summing?