English verb conjugation
MUST UNTHREAD

Regular verb: unthread - unthreaded - unthreaded

Affirmation

Simple form	V-ing form
I must unthread you must unthread he must unthread we must unthread you must unthread they must unthread	I must be unthreading you must be unthreading he must be unthreading we must be unthreading you must be unthreading they must be unthreading
Perfect	V-ing perfect
I must have unthreaded you must have unthreaded he must have unthreaded we must have unthreaded you must have unthreaded they must have unthreaded	I must have been unthreading you must have been unthreading he must have been unthreading we must have been unthreading you must have been unthreading they must have been unthreading

Negation

Simple form	V-ing form
I mustn't unthread you mustn't unthread he mustn't unthread we mustn't unthread you mustn't unthread they mustn't unthread	I mustn't be unthreading you mustn't be unthreading he mustn't be unthreading we mustn't be unthreading you mustn't be unthreading they mustn't be unthreading
Perfect	V-ing perfect
I mustn't have unthreaded you mustn't have unthreaded he mustn't have unthreaded we mustn't have unthreaded you mustn't have unthreaded they mustn't have unthreaded	I mustn't have been unthreading you mustn't have been unthreading he mustn't have been unthreading we mustn't have been unthreading you mustn't have been unthreading they mustn't have been unthreading

Interrogative form

Simple form	V-ing form
must I unthread? must you unthread? must he unthread? must we unthread? must you unthread? must they unthread?	must I be unthreading? must you be unthreading? must he be unthreading? must we be unthreading? must you be unthreading? must they be unthreading?
Perfect	V-ing perfect
must I have unthreaded? must you have unthreaded? must he have unthreaded? must we have unthreaded? must you have unthreaded? must they have unthreaded?	must I have been unthreading? must you have been unthreading? must he have been unthreading? must we have been unthreading? must you have been unthreading? must they have been unthreading?

Interro-negative form

Simple form	V-ing form
mustn't I unthread? mustn't you unthread? mustn't he unthread? mustn't we unthread? mustn't you unthread? mustn't they unthread?	mustn't I be unthreading? mustn't you be unthreading? mustn't he be unthreading? mustn't we be unthreading? mustn't you be unthreading? mustn't they be unthreading?
Perfect	V-ing perfect
mustn't I have unthreaded? mustn't you have unthreaded? mustn't he have unthreaded? mustn't we have unthreaded? mustn't you have unthreaded? mustn't they have unthreaded?	mustn't I have been unthreading? mustn't you have been unthreading? mustn't he have been unthreading? mustn't we have been unthreading? mustn't you have been unthreading? mustn't they have been unthreading?