must preacknowledge
Regular verb: preacknowledge - preacknowledged- preacknowledged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must preacknowledge
you must preacknowledge
she must preacknowledge
we must preacknowledge
you must preacknowledge
they must preacknowledge 	I must be preacknowledging
you must be preacknowledging
she must be preacknowledging
we must be preacknowledging
you must be preacknowledging
they must be preacknowledging	I must have preacknowledged
you must have preacknowledged
she must have preacknowledged
we must have preacknowledged
you must have preacknowledged
they must have preacknowledged	I must have been preacknowledging
you must have been preacknowledging
she must have been preacknowledging
we must have been preacknowledging
you must have been preacknowledging
they must have been preacknowledging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not preacknowledge
you must not preacknowledge
she must not preacknowledge
we must not preacknowledge
you must not preacknowledge
they must not preacknowledge 	I must not be preacknowledging
you must not be preacknowledging
she must not be preacknowledging
we must not be preacknowledging
you must not be preacknowledging
they must not be preacknowledging	I must not have preacknowledged
you must not have preacknowledged
she must not have preacknowledged
we must not have preacknowledged
you must not have preacknowledged
they must not have preacknowledged	I must not have been preacknowledging
you must not have been preacknowledging
she must not have been preacknowledging
we must not have been preacknowledging
you must not have been preacknowledging
they must not have been preacknowledging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I preacknowledge?
must you preacknowledge?
must she preacknowledge?
must we preacknowledge?
must you preacknowledge?
must they preacknowledge? 	must I be preacknowledging?
must you be preacknowledging?
must she be preacknowledging?
must we be preacknowledging?
must you be preacknowledging?
must they be preacknowledging? 	must I have preacknowledged?
must you have preacknowledged?
must she have preacknowledged?
must we have preacknowledged?
must you have preacknowledged?
must they have preacknowledged? 	must I have been preacknowledging?
must you have been preacknowledging?
must she have been preacknowledging?
must we have been preacknowledging?
must you have been preacknowledging?
must they have been preacknowledging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not preacknowledge?
must you not preacknowledge?
must she not preacknowledge?
must we not preacknowledge?
must you not preacknowledge?
must they not preacknowledge? 	must I not be preacknowledging?
must you not be preacknowledging?
must she not be preacknowledging?
must we not be preacknowledging?
must you not be preacknowledging?
must they not be preacknowledging? 	must I not have preacknowledged?
must you not have preacknowledged?
must she not have preacknowledged?
must we not have preacknowledged?
must you not have preacknowledged?
must they not have preacknowledged? 	must I not have been preacknowledging?
must you not have been preacknowledging?
must she not have been preacknowledging?
must we not have been preacknowledging?
must you not have been preacknowledging?
must they not have been preacknowledging?