English verb conjugation
MUST YARN

Regular verb: yarn - yarned - yarned

Affirmation

Simple form	V-ing form
I must yarn you must yarn he must yarn we must yarn you must yarn they must yarn	I must be yarning you must be yarning he must be yarning we must be yarning you must be yarning they must be yarning
Perfect	V-ing perfect
I must have yarned you must have yarned he must have yarned we must have yarned you must have yarned they must have yarned	I must have been yarning you must have been yarning he must have been yarning we must have been yarning you must have been yarning they must have been yarning

Negation

Simple form	V-ing form
I mustn't yarn you mustn't yarn he mustn't yarn we mustn't yarn you mustn't yarn they mustn't yarn	I mustn't be yarning you mustn't be yarning he mustn't be yarning we mustn't be yarning you mustn't be yarning they mustn't be yarning
Perfect	V-ing perfect
I mustn't have yarned you mustn't have yarned he mustn't have yarned we mustn't have yarned you mustn't have yarned they mustn't have yarned	I mustn't have been yarning you mustn't have been yarning he mustn't have been yarning we mustn't have been yarning you mustn't have been yarning they mustn't have been yarning

Interrogative form

Simple form	V-ing form
must I yarn? must you yarn? must he yarn? must we yarn? must you yarn? must they yarn?	must I be yarning? must you be yarning? must he be yarning? must we be yarning? must you be yarning? must they be yarning?
Perfect	V-ing perfect
must I have yarned? must you have yarned? must he have yarned? must we have yarned? must you have yarned? must they have yarned?	must I have been yarning? must you have been yarning? must he have been yarning? must we have been yarning? must you have been yarning? must they have been yarning?

Interro-negative form

Simple form	V-ing form
mustn't I yarn? mustn't you yarn? mustn't he yarn? mustn't we yarn? mustn't you yarn? mustn't they yarn?	mustn't I be yarning? mustn't you be yarning? mustn't he be yarning? mustn't we be yarning? mustn't you be yarning? mustn't they be yarning?
Perfect	V-ing perfect
mustn't I have yarned? mustn't you have yarned? mustn't he have yarned? mustn't we have yarned? mustn't you have yarned? mustn't they have yarned?	mustn't I have been yarning? mustn't you have been yarning? mustn't he have been yarning? mustn't we have been yarning? mustn't you have been yarning? mustn't they have been yarning?