could calk
Regular verb: calk - calked- calked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could calk
you could calk
she could calk
we could calk
you could calk
they could calk 	I could be calking
you could be calking
she could be calking
we could be calking
you could be calking
they could be calking	I could have calked
you could have calked
she could have calked
we could have calked
you could have calked
they could have calked	I could have been calking
you could have been calking
she could have been calking
we could have been calking
you could have been calking
they could have been calking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't calk
you couldn't calk
she couldn't calk
we couldn't calk
you couldn't calk
they couldn't calk 	I couldn't be calking
you couldn't be calking
she couldn't be calking
we couldn't be calking
you couldn't be calking
they couldn't be calking	I couldn't have calked
you couldn't have calked
she couldn't have calked
we couldn't have calked
you couldn't have calked
they couldn't have calked	I couldn't have been calking
you couldn't have been calking
she couldn't have been calking
we couldn't have been calking
you couldn't have been calking
they couldn't have been calking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I calk?
could you calk?
could she calk?
could we calk?
could you calk?
could they calk? 	could I be calking?
could you be calking?
could she be calking?
could we be calking?
could you be calking?
could they be calking? 	could I have calked?
could you have calked?
could she have calked?
could we have calked?
could you have calked?
could they have calked? 	could I have been calking?
could you have been calking?
could she have been calking?
could we have been calking?
could you have been calking?
could they have been calking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I calk?
couldn't you calk?
couldn't she calk?
couldn't we calk?
couldn't you calk?
couldn't they calk? 	couldn't I be calking?
couldn't you be calking?
couldn't she be calking?
couldn't we be calking?
couldn't you be calking?
couldn't they be calking? 	couldn't I have calked?
couldn't you have calked?
couldn't she have calked?
couldn't we have calked?
couldn't you have calked?
couldn't they have calked? 	couldn't I have been calking?
couldn't you have been calking?
couldn't she have been calking?
couldn't we have been calking?
couldn't you have been calking?
couldn't they have been calking?