English verb conjugation
COULD CLACK

Regular verb: clack - clacked - clacked

Affirmation

Simple form	V-ing form
I could clack you could clack he could clack we could clack you could clack they could clack	I could be clacking you could be clacking he could be clacking we could be clacking you could be clacking they could be clacking
Perfect	V-ing perfect
I could have clacked you could have clacked he could have clacked we could have clacked you could have clacked they could have clacked	I could have been clacking you could have been clacking he could have been clacking we could have been clacking you could have been clacking they could have been clacking

Negation

Simple form	V-ing form
I couldn't clack you couldn't clack he couldn't clack we couldn't clack you couldn't clack they couldn't clack	I couldn't be clacking you couldn't be clacking he couldn't be clacking we couldn't be clacking you couldn't be clacking they couldn't be clacking
Perfect	V-ing perfect
I couldn't have clacked you couldn't have clacked he couldn't have clacked we couldn't have clacked you couldn't have clacked they couldn't have clacked	I couldn't have been clacking you couldn't have been clacking he couldn't have been clacking we couldn't have been clacking you couldn't have been clacking they couldn't have been clacking

Interrogative form

Simple form	V-ing form
could I clack? could you clack? could he clack? could we clack? could you clack? could they clack?	could I be clacking? could you be clacking? could he be clacking? could we be clacking? could you be clacking? could they be clacking?
Perfect	V-ing perfect
could I have clacked? could you have clacked? could he have clacked? could we have clacked? could you have clacked? could they have clacked?	could I have been clacking? could you have been clacking? could he have been clacking? could we have been clacking? could you have been clacking? could they have been clacking?

Interro-negative form

Simple form	V-ing form
couldn't I clack? couldn't you clack? couldn't he clack? couldn't we clack? couldn't you clack? couldn't they clack?	couldn't I be clacking? couldn't you be clacking? couldn't he be clacking? couldn't we be clacking? couldn't you be clacking? couldn't they be clacking?
Perfect	V-ing perfect
couldn't I have clacked? couldn't you have clacked? couldn't he have clacked? couldn't we have clacked? couldn't you have clacked? couldn't they have clacked?	couldn't I have been clacking? couldn't you have been clacking? couldn't he have been clacking? couldn't we have been clacking? couldn't you have been clacking? couldn't they have been clacking?