must unstrap
Regular verb: unstrap - unstrapped- unstrapped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must unstrap
you must unstrap
she must unstrap
we must unstrap
you must unstrap
they must unstrap 	I must be unstrapping
you must be unstrapping
she must be unstrapping
we must be unstrapping
you must be unstrapping
they must be unstrapping	I must have unstrapped
you must have unstrapped
she must have unstrapped
we must have unstrapped
you must have unstrapped
they must have unstrapped	I must have been unstrapping
you must have been unstrapping
she must have been unstrapping
we must have been unstrapping
you must have been unstrapping
they must have been unstrapping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not unstrap
you must not unstrap
she must not unstrap
we must not unstrap
you must not unstrap
they must not unstrap 	I must not be unstrapping
you must not be unstrapping
she must not be unstrapping
we must not be unstrapping
you must not be unstrapping
they must not be unstrapping	I must not have unstrapped
you must not have unstrapped
she must not have unstrapped
we must not have unstrapped
you must not have unstrapped
they must not have unstrapped	I must not have been unstrapping
you must not have been unstrapping
she must not have been unstrapping
we must not have been unstrapping
you must not have been unstrapping
they must not have been unstrapping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I unstrap?
must you unstrap?
must she unstrap?
must we unstrap?
must you unstrap?
must they unstrap? 	must I be unstrapping?
must you be unstrapping?
must she be unstrapping?
must we be unstrapping?
must you be unstrapping?
must they be unstrapping? 	must I have unstrapped?
must you have unstrapped?
must she have unstrapped?
must we have unstrapped?
must you have unstrapped?
must they have unstrapped? 	must I have been unstrapping?
must you have been unstrapping?
must she have been unstrapping?
must we have been unstrapping?
must you have been unstrapping?
must they have been unstrapping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not unstrap?
must you not unstrap?
must she not unstrap?
must we not unstrap?
must you not unstrap?
must they not unstrap? 	must I not be unstrapping?
must you not be unstrapping?
must she not be unstrapping?
must we not be unstrapping?
must you not be unstrapping?
must they not be unstrapping? 	must I not have unstrapped?
must you not have unstrapped?
must she not have unstrapped?
must we not have unstrapped?
must you not have unstrapped?
must they not have unstrapped? 	must I not have been unstrapping?
must you not have been unstrapping?
must she not have been unstrapping?
must we not have been unstrapping?
must you not have been unstrapping?
must they not have been unstrapping?