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 could not clack you could not clack he could not clack we could not clack you could not clack they could not clack	I could not be clacking you could not be clacking he could not be clacking we could not be clacking you could not be clacking they could not be clacking
Perfect	V-ing perfect
I could not have clacked you could not have clacked he could not have clacked we could not have clacked you could not have clacked they could not have clacked	I could not have been clacking you could not have been clacking he could not have been clacking we could not have been clacking you could not have been clacking they could not 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
could I not clack? could you not clack? could he not clack? could we not clack? could you not clack? could they not clack?	could I not be clacking? could you not be clacking? could he not be clacking? could we not be clacking? could you not be clacking? could they not be clacking?
Perfect	V-ing perfect
could I not have clacked? could you not have clacked? could he not have clacked? could we not have clacked? could you not have clacked? could they not have clacked?	could I not have been clacking? could you not have been clacking? could he not have been clacking? could we not have been clacking? could you not have been clacking? could they not have been clacking?