can frown
Regular verb: frown - frowned- frowned

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