English verb conjugation
MUST FROWN

Regular verb: frown - frowned - frowned

Affirmation

Simple form	V-ing form
I must frown you must frown he must frown we must frown you must frown they must frown	I must be frowning you must be frowning he must be frowning we must be frowning you must be frowning they must be frowning
Perfect	V-ing perfect
I must have frowned you must have frowned he must have frowned we must have frowned you must have frowned they must have frowned	I must have been frowning you must have been frowning he must have been frowning we must have been frowning you must have been frowning they must have been frowning

Negation

Simple form	V-ing form
I must not frown you must not frown he must not frown we must not frown you must not frown they must not frown	I must not be frowning you must not be frowning he must not be frowning we must not be frowning you must not be frowning they must not be frowning
Perfect	V-ing perfect
I must not have frowned you must not have frowned he must not have frowned we must not have frowned you must not have frowned they must not have frowned	I must not have been frowning you must not have been frowning he must not have been frowning we must not have been frowning you must not have been frowning they must not have been frowning

Interrogative form

Simple form	V-ing form
must I frown? must you frown? must he frown? must we frown? must you frown? must they frown?	must I be frowning? must you be frowning? must he be frowning? must we be frowning? must you be frowning? must they be frowning?
Perfect	V-ing perfect
must I have frowned? must you have frowned? must he have frowned? must we have frowned? must you have frowned? must they have frowned?	must I have been frowning? must you have been frowning? must he have been frowning? must we have been frowning? must you have been frowning? must they have been frowning?

Interro-negative form

Simple form	V-ing form
must I not frown? must you not frown? must he not frown? must we not frown? must you not frown? must they not frown?	must I not be frowning? must you not be frowning? must he not be frowning? must we not be frowning? must you not be frowning? must they not be frowning?
Perfect	V-ing perfect
must I not have frowned? must you not have frowned? must he not have frowned? must we not have frowned? must you not have frowned? must they not have frowned?	must I not have been frowning? must you not have been frowning? must he not have been frowning? must we not have been frowning? must you not have been frowning? must they not have been frowning?