English verb conjugation
CAN FROWN

Regular verb: frown - frowned - frowned

Affirmation

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

Negation

Simple form	V-ing form
I can't frown you can't frown he can't frown we can't frown you can't frown they can't frown	I can't be frowning you can't be frowning he can't be frowning we can't be frowning you can't be frowning they can't be frowning
Perfect	V-ing perfect
I can't have frowned you can't have frowned he can't have frowned we can't have frowned you can't have frowned they can't have frowned	I can't have been frowning you can't have been frowning he can't have been frowning we can't have been frowning you can't have been frowning they can't have been frowning

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can't I frown? can't you frown? can't he frown? can't we frown? can't you frown? can't they frown?	can't I be frowning? can't you be frowning? can't he be frowning? can't we be frowning? can't you be frowning? can't they be frowning?
Perfect	V-ing perfect
can't I have frowned? can't you have frowned? can't he have frowned? can't we have frowned? can't you have frowned? can't they have frowned?	can't I have been frowning? can't you have been frowning? can't he have been frowning? can't we have been frowning? can't you have been frowning? can't they have been frowning?