I can calk you can calk he can calk we can calk you can calk they can calk
V-ing form
I can be calking you can be calking he can be calking we can be calking you can be calking they can be calking
Perfect
I can have calked you can have calked he can have calked we can have calked you can have calked they can have calked
V-ing perfect
I can have been calking you can have been calking he can have been calking we can have been calking you can have been calking they can have been calking
Negation
Simple form
I can't calk you can't calk he can't calk we can't calk you can't calk they can't calk
V-ing form
I can't be calking you can't be calking he can't be calking we can't be calking you can't be calking they can't be calking
Perfect
I can't have calked you can't have calked he can't have calked we can't have calked you can't have calked they can't have calked
V-ing perfect
I can't have been calking you can't have been calking he can't have been calking we can't have been calking you can't have been calking they can't have been calking
Interrogative form
Simple form
can I calk? can you calk? can he calk? can we calk? can you calk? can they calk?
V-ing form
can I be calking? can you be calking? can he be calking? can we be calking? can you be calking? can they be calking?
Perfect
can I have calked? can you have calked? can he have calked? can we have calked? can you have calked? can they have calked?
V-ing perfect
can I have been calking? can you have been calking? can he have been calking? can we have been calking? can you have been calking? can they have been calking?
Interro-negative form
Simple form
can't I calk? can't you calk? can't he calk? can't we calk? can't you calk? can't they calk?
V-ing form
can't I be calking? can't you be calking? can't he be calking? can't we be calking? can't you be calking? can't they be calking?
Perfect
can't I have calked? can't you have calked? can't he have calked? can't we have calked? can't you have calked? can't they have calked?
V-ing perfect
can't I have been calking? can't you have been calking? can't he have been calking? can't we have been calking? can't you have been calking? can't they have been calking?