must purchase
Regular verb: purchase - purchased- purchased

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must purchase
you must purchase
she must purchase
we must purchase
you must purchase
they must purchase 	I must be purchasing
you must be purchasing
she must be purchasing
we must be purchasing
you must be purchasing
they must be purchasing	I must have purchased
you must have purchased
she must have purchased
we must have purchased
you must have purchased
they must have purchased	I must have been purchasing
you must have been purchasing
she must have been purchasing
we must have been purchasing
you must have been purchasing
they must have been purchasing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't purchase
you mustn't purchase
she mustn't purchase
we mustn't purchase
you mustn't purchase
they mustn't purchase 	I mustn't be purchasing
you mustn't be purchasing
she mustn't be purchasing
we mustn't be purchasing
you mustn't be purchasing
they mustn't be purchasing	I mustn't have purchased
you mustn't have purchased
she mustn't have purchased
we mustn't have purchased
you mustn't have purchased
they mustn't have purchased	I mustn't have been purchasing
you mustn't have been purchasing
she mustn't have been purchasing
we mustn't have been purchasing
you mustn't have been purchasing
they mustn't have been purchasing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I purchase?
must you purchase?
must she purchase?
must we purchase?
must you purchase?
must they purchase? 	must I be purchasing?
must you be purchasing?
must she be purchasing?
must we be purchasing?
must you be purchasing?
must they be purchasing? 	must I have purchased?
must you have purchased?
must she have purchased?
must we have purchased?
must you have purchased?
must they have purchased? 	must I have been purchasing?
must you have been purchasing?
must she have been purchasing?
must we have been purchasing?
must you have been purchasing?
must they have been purchasing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I purchase?
mustn't you purchase?
mustn't she purchase?
mustn't we purchase?
mustn't you purchase?
mustn't they purchase? 	mustn't I be purchasing?
mustn't you be purchasing?
mustn't she be purchasing?
mustn't we be purchasing?
mustn't you be purchasing?
mustn't they be purchasing? 	mustn't I have purchased?
mustn't you have purchased?
mustn't she have purchased?
mustn't we have purchased?
mustn't you have purchased?
mustn't they have purchased? 	mustn't I have been purchasing?
mustn't you have been purchasing?
mustn't she have been purchasing?
mustn't we have been purchasing?
mustn't you have been purchasing?
mustn't they have been purchasing?