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 may not tighten you may not tighten he may not tighten we may not tighten you may not tighten they may not tighten	I may not be tightening you may not be tightening he may not be tightening we may not be tightening you may not be tightening they may not be tightening
Perfect	V-ing perfect
I may not have tightened you may not have tightened he may not have tightened we may not have tightened you may not have tightened they may not have tightened	I may not have been tightening you may not have been tightening he may not have been tightening we may not have been tightening you may not have been tightening they may not 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
may I not tighten? may you not tighten? may he not tighten? may we not tighten? may you not tighten? may they not tighten?	may I not be tightening? may you not be tightening? may he not be tightening? may we not be tightening? may you not be tightening? may they not be tightening?
Perfect	V-ing perfect
may I not have tightened? may you not have tightened? may he not have tightened? may we not have tightened? may you not have tightened? may they not have tightened?	may I not have been tightening? may you not have been tightening? may he not have been tightening? may we not have been tightening? may you not have been tightening? may they not have been tightening?