I must pierce you must pierce she must pierce we must pierce you must pierce they must pierce
V-ing form
I must be piercing you must be piercing she must be piercing we must be piercing you must be piercing they must be piercing
Perfect
I must have pierced you must have pierced she must have pierced we must have pierced you must have pierced they must have pierced
V-ing perfect
I must have been piercing you must have been piercing she must have been piercing we must have been piercing you must have been piercing they must have been piercing
Negation
Simple form
I must not pierce you must not pierce she must not pierce we must not pierce you must not pierce they must not pierce
V-ing form
I must not be piercing you must not be piercing she must not be piercing we must not be piercing you must not be piercing they must not be piercing
Perfect
I must not have pierced you must not have pierced she must not have pierced we must not have pierced you must not have pierced they must not have pierced
V-ing perfect
I must not have been piercing you must not have been piercing she must not have been piercing we must not have been piercing you must not have been piercing they must not have been piercing
Interrogative form
Simple form
must I pierce? must you pierce? must she pierce? must we pierce? must you pierce? must they pierce?
V-ing form
must I be piercing? must you be piercing? must she be piercing? must we be piercing? must you be piercing? must they be piercing?
Perfect
must I have pierced? must you have pierced? must she have pierced? must we have pierced? must you have pierced? must they have pierced?
V-ing perfect
must I have been piercing? must you have been piercing? must she have been piercing? must we have been piercing? must you have been piercing? must they have been piercing?
Interro-negative form
Simple form
must I not pierce? must you not pierce? must she not pierce? must we not pierce? must you not pierce? must they not pierce?
V-ing form
must I not be piercing? must you not be piercing? must she not be piercing? must we not be piercing? must you not be piercing? must they not be piercing?
Perfect
must I not have pierced? must you not have pierced? must she not have pierced? must we not have pierced? must you not have pierced? must they not have pierced?
V-ing perfect
must I not have been piercing? must you not have been piercing? must she not have been piercing? must we not have been piercing? must you not have been piercing? must they not have been piercing?