English verb conjugation
COULD FROWN

Regular verb: frown - frowned - frowned

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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