English verb conjugation
MAY TIGHTEN

Regular verb: tighten - tightened - tightened

Affirmation

Simple form	V-ing form
I may tighten you may tighten he may tighten we may tighten you may tighten they may tighten	I may be tightening you may be tightening he may be tightening we may be tightening you may be tightening they may be tightening
Perfect	V-ing perfect
I may have tightened you may have tightened he may have tightened we may have tightened you may have tightened they may have tightened	I may have been tightening you may have been tightening he may have been tightening we may have been tightening you may have been tightening they may have been tightening

Negation

Simple form	V-ing form
I mayn't tighten you mayn't tighten he mayn't tighten we mayn't tighten you mayn't tighten they mayn't tighten	I mayn't be tightening you mayn't be tightening he mayn't be tightening we mayn't be tightening you mayn't be tightening they mayn't be tightening
Perfect	V-ing perfect
I mayn't have tightened you mayn't have tightened he mayn't have tightened we mayn't have tightened you mayn't have tightened they mayn't have tightened	I mayn't have been tightening you mayn't have been tightening he mayn't have been tightening we mayn't have been tightening you mayn't have been tightening they mayn't have been tightening

Interrogative form

Simple form	V-ing form
may I tighten? may you tighten? may he tighten? may we tighten? may you tighten? may they tighten?	may I be tightening? may you be tightening? may he be tightening? may we be tightening? may you be tightening? may they be tightening?
Perfect	V-ing perfect
may I have tightened? may you have tightened? may he have tightened? may we have tightened? may you have tightened? may they have tightened?	may I have been tightening? may you have been tightening? may he have been tightening? may we have been tightening? may you have been tightening? may they have been tightening?

Interro-negative form

Simple form	V-ing form
mayn't I tighten? mayn't you tighten? mayn't he tighten? mayn't we tighten? mayn't you tighten? mayn't they tighten?	mayn't I be tightening? mayn't you be tightening? mayn't he be tightening? mayn't we be tightening? mayn't you be tightening? mayn't they be tightening?
Perfect	V-ing perfect
mayn't I have tightened? mayn't you have tightened? mayn't he have tightened? mayn't we have tightened? mayn't you have tightened? mayn't they have tightened?	mayn't I have been tightening? mayn't you have been tightening? mayn't he have been tightening? mayn't we have been tightening? mayn't you have been tightening? mayn't they have been tightening?