must unstep
Verbe régulier : unstep - unsteped- unsteped

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must unstep
you must unstep
she must unstep
we must unstep
you must unstep
they must unstep 	I must be unsteping
you must be unsteping
she must be unsteping
we must be unsteping
you must be unsteping
they must be unsteping	I must have unsteped
you must have unsteped
she must have unsteped
we must have unsteped
you must have unsteped
they must have unsteped	I must have been unsteping
you must have been unsteping
she must have been unsteping
we must have been unsteping
you must have been unsteping
they must have been unsteping	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't unstep
you mustn't unstep
she mustn't unstep
we mustn't unstep
you mustn't unstep
they mustn't unstep 	I mustn't be unsteping
you mustn't be unsteping
she mustn't be unsteping
we mustn't be unsteping
you mustn't be unsteping
they mustn't be unsteping	I mustn't have unsteped
you mustn't have unsteped
she mustn't have unsteped
we mustn't have unsteped
you mustn't have unsteped
they mustn't have unsteped	I mustn't have been unsteping
you mustn't have been unsteping
she mustn't have been unsteping
we mustn't have been unsteping
you mustn't have been unsteping
they mustn't have been unsteping	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I unstep?
must you unstep?
must she unstep?
must we unstep?
must you unstep?
must they unstep? 	must I be unsteping?
must you be unsteping?
must she be unsteping?
must we be unsteping?
must you be unsteping?
must they be unsteping? 	must I have unsteped?
must you have unsteped?
must she have unsteped?
must we have unsteped?
must you have unsteped?
must they have unsteped? 	must I have been unsteping?
must you have been unsteping?
must she have been unsteping?
must we have been unsteping?
must you have been unsteping?
must they have been unsteping? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I unstep?
mustn't you unstep?
mustn't she unstep?
mustn't we unstep?
mustn't you unstep?
mustn't they unstep? 	mustn't I be unsteping?
mustn't you be unsteping?
mustn't she be unsteping?
mustn't we be unsteping?
mustn't you be unsteping?
mustn't they be unsteping? 	mustn't I have unsteped?
mustn't you have unsteped?
mustn't she have unsteped?
mustn't we have unsteped?
mustn't you have unsteped?
mustn't they have unsteped? 	mustn't I have been unsteping?
mustn't you have been unsteping?
mustn't she have been unsteping?
mustn't we have been unsteping?
mustn't you have been unsteping?
mustn't they have been unsteping?