English verb conjugation
COULD FILL

Regular verb: fill - filled - filled

Affirmation

Simple form	V-ing form
I could fill you could fill he could fill we could fill you could fill they could fill	I could be filling you could be filling he could be filling we could be filling you could be filling they could be filling
Perfect	V-ing perfect
I could have filled you could have filled he could have filled we could have filled you could have filled they could have filled	I could have been filling you could have been filling he could have been filling we could have been filling you could have been filling they could have been filling

Negation

Simple form	V-ing form
I could not fill you could not fill he could not fill we could not fill you could not fill they could not fill	I could not be filling you could not be filling he could not be filling we could not be filling you could not be filling they could not be filling
Perfect	V-ing perfect
I could not have filled you could not have filled he could not have filled we could not have filled you could not have filled they could not have filled	I could not have been filling you could not have been filling he could not have been filling we could not have been filling you could not have been filling they could not have been filling

Interrogative form

Simple form	V-ing form
could I fill? could you fill? could he fill? could we fill? could you fill? could they fill?	could I be filling? could you be filling? could he be filling? could we be filling? could you be filling? could they be filling?
Perfect	V-ing perfect
could I have filled? could you have filled? could he have filled? could we have filled? could you have filled? could they have filled?	could I have been filling? could you have been filling? could he have been filling? could we have been filling? could you have been filling? could they have been filling?

Interro-negative form

Simple form	V-ing form
could I not fill? could you not fill? could he not fill? could we not fill? could you not fill? could they not fill?	could I not be filling? could you not be filling? could he not be filling? could we not be filling? could you not be filling? could they not be filling?
Perfect	V-ing perfect
could I not have filled? could you not have filled? could he not have filled? could we not have filled? could you not have filled? could they not have filled?	could I not have been filling? could you not have been filling? could he not have been filling? could we not have been filling? could you not have been filling? could they not have been filling?