must preplan
Regular verb: preplan - preplaned- preplaned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must preplan
you must preplan
she must preplan
we must preplan
you must preplan
they must preplan 	I must be preplaning
you must be preplaning
she must be preplaning
we must be preplaning
you must be preplaning
they must be preplaning	I must have preplaned
you must have preplaned
she must have preplaned
we must have preplaned
you must have preplaned
they must have preplaned	I must have been preplaning
you must have been preplaning
she must have been preplaning
we must have been preplaning
you must have been preplaning
they must have been preplaning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't preplan
you mustn't preplan
she mustn't preplan
we mustn't preplan
you mustn't preplan
they mustn't preplan 	I mustn't be preplaning
you mustn't be preplaning
she mustn't be preplaning
we mustn't be preplaning
you mustn't be preplaning
they mustn't be preplaning	I mustn't have preplaned
you mustn't have preplaned
she mustn't have preplaned
we mustn't have preplaned
you mustn't have preplaned
they mustn't have preplaned	I mustn't have been preplaning
you mustn't have been preplaning
she mustn't have been preplaning
we mustn't have been preplaning
you mustn't have been preplaning
they mustn't have been preplaning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I preplan?
must you preplan?
must she preplan?
must we preplan?
must you preplan?
must they preplan? 	must I be preplaning?
must you be preplaning?
must she be preplaning?
must we be preplaning?
must you be preplaning?
must they be preplaning? 	must I have preplaned?
must you have preplaned?
must she have preplaned?
must we have preplaned?
must you have preplaned?
must they have preplaned? 	must I have been preplaning?
must you have been preplaning?
must she have been preplaning?
must we have been preplaning?
must you have been preplaning?
must they have been preplaning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I preplan?
mustn't you preplan?
mustn't she preplan?
mustn't we preplan?
mustn't you preplan?
mustn't they preplan? 	mustn't I be preplaning?
mustn't you be preplaning?
mustn't she be preplaning?
mustn't we be preplaning?
mustn't you be preplaning?
mustn't they be preplaning? 	mustn't I have preplaned?
mustn't you have preplaned?
mustn't she have preplaned?
mustn't we have preplaned?
mustn't you have preplaned?
mustn't they have preplaned? 	mustn't I have been preplaning?
mustn't you have been preplaning?
mustn't she have been preplaning?
mustn't we have been preplaning?
mustn't you have been preplaning?
mustn't they have been preplaning?