must maintain
Regular verb: maintain - maintained- maintained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must maintain
you must maintain
she must maintain
we must maintain
you must maintain
they must maintain 	I must be maintaining
you must be maintaining
she must be maintaining
we must be maintaining
you must be maintaining
they must be maintaining	I must have maintained
you must have maintained
she must have maintained
we must have maintained
you must have maintained
they must have maintained	I must have been maintaining
you must have been maintaining
she must have been maintaining
we must have been maintaining
you must have been maintaining
they must have been maintaining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't maintain
you mustn't maintain
she mustn't maintain
we mustn't maintain
you mustn't maintain
they mustn't maintain 	I mustn't be maintaining
you mustn't be maintaining
she mustn't be maintaining
we mustn't be maintaining
you mustn't be maintaining
they mustn't be maintaining	I mustn't have maintained
you mustn't have maintained
she mustn't have maintained
we mustn't have maintained
you mustn't have maintained
they mustn't have maintained	I mustn't have been maintaining
you mustn't have been maintaining
she mustn't have been maintaining
we mustn't have been maintaining
you mustn't have been maintaining
they mustn't have been maintaining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I maintain?
must you maintain?
must she maintain?
must we maintain?
must you maintain?
must they maintain? 	must I be maintaining?
must you be maintaining?
must she be maintaining?
must we be maintaining?
must you be maintaining?
must they be maintaining? 	must I have maintained?
must you have maintained?
must she have maintained?
must we have maintained?
must you have maintained?
must they have maintained? 	must I have been maintaining?
must you have been maintaining?
must she have been maintaining?
must we have been maintaining?
must you have been maintaining?
must they have been maintaining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I maintain?
mustn't you maintain?
mustn't she maintain?
mustn't we maintain?
mustn't you maintain?
mustn't they maintain? 	mustn't I be maintaining?
mustn't you be maintaining?
mustn't she be maintaining?
mustn't we be maintaining?
mustn't you be maintaining?
mustn't they be maintaining? 	mustn't I have maintained?
mustn't you have maintained?
mustn't she have maintained?
mustn't we have maintained?
mustn't you have maintained?
mustn't they have maintained? 	mustn't I have been maintaining?
mustn't you have been maintaining?
mustn't she have been maintaining?
mustn't we have been maintaining?
mustn't you have been maintaining?
mustn't they have been maintaining?