I must retighten you must retighten she must retighten we must retighten you must retighten they must retighten
V-ing form
I must be retightening you must be retightening she must be retightening we must be retightening you must be retightening they must be retightening
Perfect
I must have retightened you must have retightened she must have retightened we must have retightened you must have retightened they must have retightened
V-ing perfect
I must have been retightening you must have been retightening she must have been retightening we must have been retightening you must have been retightening they must have been retightening
Negation
Simple form
I must not retighten you must not retighten she must not retighten we must not retighten you must not retighten they must not retighten
V-ing form
I must not be retightening you must not be retightening she must not be retightening we must not be retightening you must not be retightening they must not be retightening
Perfect
I must not have retightened you must not have retightened she must not have retightened we must not have retightened you must not have retightened they must not have retightened
V-ing perfect
I must not have been retightening you must not have been retightening she must not have been retightening we must not have been retightening you must not have been retightening they must not have been retightening
Interrogative form
Simple form
must I retighten? must you retighten? must she retighten? must we retighten? must you retighten? must they retighten?
V-ing form
must I be retightening? must you be retightening? must she be retightening? must we be retightening? must you be retightening? must they be retightening?
Perfect
must I have retightened? must you have retightened? must she have retightened? must we have retightened? must you have retightened? must they have retightened?
V-ing perfect
must I have been retightening? must you have been retightening? must she have been retightening? must we have been retightening? must you have been retightening? must they have been retightening?
Interro-negative form
Simple form
must I not retighten? must you not retighten? must she not retighten? must we not retighten? must you not retighten? must they not retighten?
V-ing form
must I not be retightening? must you not be retightening? must she not be retightening? must we not be retightening? must you not be retightening? must they not be retightening?
Perfect
must I not have retightened? must you not have retightened? must she not have retightened? must we not have retightened? must you not have retightened? must they not have retightened?
V-ing perfect
must I not have been retightening? must you not have been retightening? must she not have been retightening? must we not have been retightening? must you not have been retightening? must they not have been retightening?