must prepurchase
Regular verb: prepurchase - prepurchased- prepurchased

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must prepurchase
you must prepurchase
she must prepurchase
we must prepurchase
you must prepurchase
they must prepurchase 	I must be prepurchasing
you must be prepurchasing
she must be prepurchasing
we must be prepurchasing
you must be prepurchasing
they must be prepurchasing	I must have prepurchased
you must have prepurchased
she must have prepurchased
we must have prepurchased
you must have prepurchased
they must have prepurchased	I must have been prepurchasing
you must have been prepurchasing
she must have been prepurchasing
we must have been prepurchasing
you must have been prepurchasing
they must have been prepurchasing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't prepurchase
you mustn't prepurchase
she mustn't prepurchase
we mustn't prepurchase
you mustn't prepurchase
they mustn't prepurchase 	I mustn't be prepurchasing
you mustn't be prepurchasing
she mustn't be prepurchasing
we mustn't be prepurchasing
you mustn't be prepurchasing
they mustn't be prepurchasing	I mustn't have prepurchased
you mustn't have prepurchased
she mustn't have prepurchased
we mustn't have prepurchased
you mustn't have prepurchased
they mustn't have prepurchased	I mustn't have been prepurchasing
you mustn't have been prepurchasing
she mustn't have been prepurchasing
we mustn't have been prepurchasing
you mustn't have been prepurchasing
they mustn't have been prepurchasing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I prepurchase?
must you prepurchase?
must she prepurchase?
must we prepurchase?
must you prepurchase?
must they prepurchase? 	must I be prepurchasing?
must you be prepurchasing?
must she be prepurchasing?
must we be prepurchasing?
must you be prepurchasing?
must they be prepurchasing? 	must I have prepurchased?
must you have prepurchased?
must she have prepurchased?
must we have prepurchased?
must you have prepurchased?
must they have prepurchased? 	must I have been prepurchasing?
must you have been prepurchasing?
must she have been prepurchasing?
must we have been prepurchasing?
must you have been prepurchasing?
must they have been prepurchasing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I prepurchase?
mustn't you prepurchase?
mustn't she prepurchase?
mustn't we prepurchase?
mustn't you prepurchase?
mustn't they prepurchase? 	mustn't I be prepurchasing?
mustn't you be prepurchasing?
mustn't she be prepurchasing?
mustn't we be prepurchasing?
mustn't you be prepurchasing?
mustn't they be prepurchasing? 	mustn't I have prepurchased?
mustn't you have prepurchased?
mustn't she have prepurchased?
mustn't we have prepurchased?
mustn't you have prepurchased?
mustn't they have prepurchased? 	mustn't I have been prepurchasing?
mustn't you have been prepurchasing?
mustn't she have been prepurchasing?
mustn't we have been prepurchasing?
mustn't you have been prepurchasing?
mustn't they have been prepurchasing?