must unstring
Verbo irregular: unstring - unstrung- unstrung

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must unstring
you must unstring
she must unstring
we must unstring
you must unstring
they must unstring 	I must be unstringing
you must be unstringing
she must be unstringing
we must be unstringing
you must be unstringing
they must be unstringing	I must have unstrung
you must have unstrung
she must have unstrung
we must have unstrung
you must have unstrung
they must have unstrung	I must have been unstringing
you must have been unstringing
she must have been unstringing
we must have been unstringing
you must have been unstringing
they must have been unstringing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not unstring
you must not unstring
she must not unstring
we must not unstring
you must not unstring
they must not unstring 	I must not be unstringing
you must not be unstringing
she must not be unstringing
we must not be unstringing
you must not be unstringing
they must not be unstringing	I must not have unstrung
you must not have unstrung
she must not have unstrung
we must not have unstrung
you must not have unstrung
they must not have unstrung	I must not have been unstringing
you must not have been unstringing
she must not have been unstringing
we must not have been unstringing
you must not have been unstringing
they must not have been unstringing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I unstring?
must you unstring?
must she unstring?
must we unstring?
must you unstring?
must they unstring? 	must I be unstringing?
must you be unstringing?
must she be unstringing?
must we be unstringing?
must you be unstringing?
must they be unstringing? 	must I have unstrung?
must you have unstrung?
must she have unstrung?
must we have unstrung?
must you have unstrung?
must they have unstrung? 	must I have been unstringing?
must you have been unstringing?
must she have been unstringing?
must we have been unstringing?
must you have been unstringing?
must they have been unstringing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not unstring?
must you not unstring?
must she not unstring?
must we not unstring?
must you not unstring?
must they not unstring? 	must I not be unstringing?
must you not be unstringing?
must she not be unstringing?
must we not be unstringing?
must you not be unstringing?
must they not be unstringing? 	must I not have unstrung?
must you not have unstrung?
must she not have unstrung?
must we not have unstrung?
must you not have unstrung?
must they not have unstrung? 	must I not have been unstringing?
must you not have been unstringing?
must she not have been unstringing?
must we not have been unstringing?
must you not have been unstringing?
must they not have been unstringing?