could perk
Regular verb: perk - perked- perked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could perk
you could perk
she could perk
we could perk
you could perk
they could perk 	I could be perking
you could be perking
she could be perking
we could be perking
you could be perking
they could be perking	I could have perked
you could have perked
she could have perked
we could have perked
you could have perked
they could have perked	I could have been perking
you could have been perking
she could have been perking
we could have been perking
you could have been perking
they could have been perking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't perk
you couldn't perk
she couldn't perk
we couldn't perk
you couldn't perk
they couldn't perk 	I couldn't be perking
you couldn't be perking
she couldn't be perking
we couldn't be perking
you couldn't be perking
they couldn't be perking	I couldn't have perked
you couldn't have perked
she couldn't have perked
we couldn't have perked
you couldn't have perked
they couldn't have perked	I couldn't have been perking
you couldn't have been perking
she couldn't have been perking
we couldn't have been perking
you couldn't have been perking
they couldn't have been perking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I perk?
could you perk?
could she perk?
could we perk?
could you perk?
could they perk? 	could I be perking?
could you be perking?
could she be perking?
could we be perking?
could you be perking?
could they be perking? 	could I have perked?
could you have perked?
could she have perked?
could we have perked?
could you have perked?
could they have perked? 	could I have been perking?
could you have been perking?
could she have been perking?
could we have been perking?
could you have been perking?
could they have been perking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I perk?
couldn't you perk?
couldn't she perk?
couldn't we perk?
couldn't you perk?
couldn't they perk? 	couldn't I be perking?
couldn't you be perking?
couldn't she be perking?
couldn't we be perking?
couldn't you be perking?
couldn't they be perking? 	couldn't I have perked?
couldn't you have perked?
couldn't she have perked?
couldn't we have perked?
couldn't you have perked?
couldn't they have perked? 	couldn't I have been perking?
couldn't you have been perking?
couldn't she have been perking?
couldn't we have been perking?
couldn't you have been perking?
couldn't they have been perking?