English verb conjugation
COULD CHALK

Regular verb: chalk - chalked - chalked

Affirmation

Simple form	V-ing form
I could chalk you could chalk he could chalk we could chalk you could chalk they could chalk	I could be chalking you could be chalking he could be chalking we could be chalking you could be chalking they could be chalking
Perfect	V-ing perfect
I could have chalked you could have chalked he could have chalked we could have chalked you could have chalked they could have chalked	I could have been chalking you could have been chalking he could have been chalking we could have been chalking you could have been chalking they could have been chalking

Negation

Simple form	V-ing form
I couldn't chalk you couldn't chalk he couldn't chalk we couldn't chalk you couldn't chalk they couldn't chalk	I couldn't be chalking you couldn't be chalking he couldn't be chalking we couldn't be chalking you couldn't be chalking they couldn't be chalking
Perfect	V-ing perfect
I couldn't have chalked you couldn't have chalked he couldn't have chalked we couldn't have chalked you couldn't have chalked they couldn't have chalked	I couldn't have been chalking you couldn't have been chalking he couldn't have been chalking we couldn't have been chalking you couldn't have been chalking they couldn't have been chalking

Interrogative form

Simple form	V-ing form
could I chalk? could you chalk? could he chalk? could we chalk? could you chalk? could they chalk?	could I be chalking? could you be chalking? could he be chalking? could we be chalking? could you be chalking? could they be chalking?
Perfect	V-ing perfect
could I have chalked? could you have chalked? could he have chalked? could we have chalked? could you have chalked? could they have chalked?	could I have been chalking? could you have been chalking? could he have been chalking? could we have been chalking? could you have been chalking? could they have been chalking?

Interro-negative form

Simple form	V-ing form
couldn't I chalk? couldn't you chalk? couldn't he chalk? couldn't we chalk? couldn't you chalk? couldn't they chalk?	couldn't I be chalking? couldn't you be chalking? couldn't he be chalking? couldn't we be chalking? couldn't you be chalking? couldn't they be chalking?
Perfect	V-ing perfect
couldn't I have chalked? couldn't you have chalked? couldn't he have chalked? couldn't we have chalked? couldn't you have chalked? couldn't they have chalked?	couldn't I have been chalking? couldn't you have been chalking? couldn't he have been chalking? couldn't we have been chalking? couldn't you have been chalking? couldn't they have been chalking?