English verb conjugation
COULD CLERK

Regular verb: clerk - clerked - clerked

Affirmation

Simple form	V-ing form
I could clerk you could clerk he could clerk we could clerk you could clerk they could clerk	I could be clerking you could be clerking he could be clerking we could be clerking you could be clerking they could be clerking
Perfect	V-ing perfect
I could have clerked you could have clerked he could have clerked we could have clerked you could have clerked they could have clerked	I could have been clerking you could have been clerking he could have been clerking we could have been clerking you could have been clerking they could have been clerking

Negation

Simple form	V-ing form
I could not clerk you could not clerk he could not clerk we could not clerk you could not clerk they could not clerk	I could not be clerking you could not be clerking he could not be clerking we could not be clerking you could not be clerking they could not be clerking
Perfect	V-ing perfect
I could not have clerked you could not have clerked he could not have clerked we could not have clerked you could not have clerked they could not have clerked	I could not have been clerking you could not have been clerking he could not have been clerking we could not have been clerking you could not have been clerking they could not have been clerking

Interrogative form

Simple form	V-ing form
could I clerk? could you clerk? could he clerk? could we clerk? could you clerk? could they clerk?	could I be clerking? could you be clerking? could he be clerking? could we be clerking? could you be clerking? could they be clerking?
Perfect	V-ing perfect
could I have clerked? could you have clerked? could he have clerked? could we have clerked? could you have clerked? could they have clerked?	could I have been clerking? could you have been clerking? could he have been clerking? could we have been clerking? could you have been clerking? could they have been clerking?

Interro-negative form

Simple form	V-ing form
could I not clerk? could you not clerk? could he not clerk? could we not clerk? could you not clerk? could they not clerk?	could I not be clerking? could you not be clerking? could he not be clerking? could we not be clerking? could you not be clerking? could they not be clerking?
Perfect	V-ing perfect
could I not have clerked? could you not have clerked? could he not have clerked? could we not have clerked? could you not have clerked? could they not have clerked?	could I not have been clerking? could you not have been clerking? could he not have been clerking? could we not have been clerking? could you not have been clerking? could they not have been clerking?