English verb conjugation
COULD FILL

Regular verb: fill - filled - filled

Affirmation

Simple form	V-ing form
I could fill you could fill she could fill we could fill you could fill they could fill	I could be filling you could be filling she 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 she 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 she 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 couldn't fill you couldn't fill she couldn't fill we couldn't fill you couldn't fill they couldn't fill	I couldn't be filling you couldn't be filling she couldn't be filling we couldn't be filling you couldn't be filling they couldn't be filling
Perfect	V-ing perfect
I couldn't have filled you couldn't have filled she couldn't have filled we couldn't have filled you couldn't have filled they couldn't have filled	I couldn't have been filling you couldn't have been filling she couldn't have been filling we couldn't have been filling you couldn't have been filling they couldn't have been filling

Interrogative form

Simple form	V-ing form
could I fill? could you fill? could she fill? could we fill? could you fill? could they fill?	could I be filling? could you be filling? could she 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 she 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 she 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
couldn't I fill? couldn't you fill? couldn't she fill? couldn't we fill? couldn't you fill? couldn't they fill?	couldn't I be filling? couldn't you be filling? couldn't she be filling? couldn't we be filling? couldn't you be filling? couldn't they be filling?
Perfect	V-ing perfect
couldn't I have filled? couldn't you have filled? couldn't she have filled? couldn't we have filled? couldn't you have filled? couldn't they have filled?	couldn't I have been filling? couldn't you have been filling? couldn't she have been filling? couldn't we have been filling? couldn't you have been filling? couldn't they have been filling?