must back
Regelmä&szlig;iges Verb: back - backed- backed

Bestätigung 	
Einfache Form 	Form mit V-ing 	Perfekt 	Perfekt mit V-ing 	
I must back
you must back
she must back
we must back
you must back
they must back 	I must be backing
you must be backing
she must be backing
we must be backing
you must be backing
they must be backing	I must have backed
you must have backed
she must have backed
we must have backed
you must have backed
they must have backed	I must have been backing
you must have been backing
she must have been backing
we must have been backing
you must have been backing
they must have been backing	

Negation 	
Einfache Form 	Form mit V-ing 	Perfekt 	Perfekt mit V-ing 	
I mustn't back
you mustn't back
she mustn't back
we mustn't back
you mustn't back
they mustn't back 	I mustn't be backing
you mustn't be backing
she mustn't be backing
we mustn't be backing
you mustn't be backing
they mustn't be backing	I mustn't have backed
you mustn't have backed
she mustn't have backed
we mustn't have backed
you mustn't have backed
they mustn't have backed	I mustn't have been backing
you mustn't have been backing
she mustn't have been backing
we mustn't have been backing
you mustn't have been backing
they mustn't have been backing	

Fragende Form 	
Einfache Form 	Form mit V-ing 	Perfekt 	Perfekt mit V-ing 	
must I back?
must you back?
must she back?
must we back?
must you back?
must they back? 	must I be backing?
must you be backing?
must she be backing?
must we be backing?
must you be backing?
must they be backing? 	must I have backed?
must you have backed?
must she have backed?
must we have backed?
must you have backed?
must they have backed? 	must I have been backing?
must you have been backing?
must she have been backing?
must we have been backing?
must you have been backing?
must they have been backing? 	

Fragende Negation Form 	
Einfache Form 	Form mit V-ing 	Perfekt 	Perfekt mit V-ing 	
mustn't I back?
mustn't you back?
mustn't she back?
mustn't we back?
mustn't you back?
mustn't they back? 	mustn't I be backing?
mustn't you be backing?
mustn't she be backing?
mustn't we be backing?
mustn't you be backing?
mustn't they be backing? 	mustn't I have backed?
mustn't you have backed?
mustn't she have backed?
mustn't we have backed?
mustn't you have backed?
mustn't they have backed? 	mustn't I have been backing?
mustn't you have been backing?
mustn't she have been backing?
mustn't we have been backing?
mustn't you have been backing?
mustn't they have been backing?