I could seed you could seed she could seed we could seed you could seed they could seed
V-ing form
I could be seeding you could be seeding she could be seeding we could be seeding you could be seeding they could be seeding
Perfect
I could have seeded you could have seeded she could have seeded we could have seeded you could have seeded they could have seeded
V-ing perfect
I could have been seeding you could have been seeding she could have been seeding we could have been seeding you could have been seeding they could have been seeding
Negation
Simple form
I could not seed you could not seed she could not seed we could not seed you could not seed they could not seed
V-ing form
I could not be seeding you could not be seeding she could not be seeding we could not be seeding you could not be seeding they could not be seeding
Perfect
I could not have seeded you could not have seeded she could not have seeded we could not have seeded you could not have seeded they could not have seeded
V-ing perfect
I could not have been seeding you could not have been seeding she could not have been seeding we could not have been seeding you could not have been seeding they could not have been seeding
Interrogative form
Simple form
could I seed? could you seed? could she seed? could we seed? could you seed? could they seed?
V-ing form
could I be seeding? could you be seeding? could she be seeding? could we be seeding? could you be seeding? could they be seeding?
Perfect
could I have seeded? could you have seeded? could she have seeded? could we have seeded? could you have seeded? could they have seeded?
V-ing perfect
could I have been seeding? could you have been seeding? could she have been seeding? could we have been seeding? could you have been seeding? could they have been seeding?
Interro-negative form
Simple form
could I not seed? could you not seed? could she not seed? could we not seed? could you not seed? could they not seed?
V-ing form
could I not be seeding? could you not be seeding? could she not be seeding? could we not be seeding? could you not be seeding? could they not be seeding?
Perfect
could I not have seeded? could you not have seeded? could she not have seeded? could we not have seeded? could you not have seeded? could they not have seeded?
V-ing perfect
could I not have been seeding? could you not have been seeding? could she not have been seeding? could we not have been seeding? could you not have been seeding? could they not have been seeding?