must pierce
Regular verb: pierce - pierced- pierced

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must pierce
you must pierce
she must pierce
we must pierce
you must pierce
they must pierce 	I must be piercing
you must be piercing
she must be piercing
we must be piercing
you must be piercing
they must be piercing	I must have pierced
you must have pierced
she must have pierced
we must have pierced
you must have pierced
they must have pierced	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 	V-ing form 	Perfect 	V-ing perfect 	
I must not pierce
you must not pierce
she must not pierce
we must not pierce
you must not pierce
they must not pierce 	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	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	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 	V-ing form 	Perfect 	V-ing perfect 	
must I pierce?
must you pierce?
must she pierce?
must we pierce?
must you pierce?
must they pierce? 	must I be piercing?
must you be piercing?
must she be piercing?
must we be piercing?
must you be piercing?
must they be piercing? 	must I have pierced?
must you have pierced?
must she have pierced?
must we have pierced?
must you have pierced?
must they have pierced? 	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 	V-ing form 	Perfect 	V-ing perfect 	
must I not pierce?
must you not pierce?
must she not pierce?
must we not pierce?
must you not pierce?
must they not pierce? 	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? 	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? 	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?