I could befog you could befog she could befog we could befog you could befog they could befog
V-ing form
I could be befoging you could be befoging she could be befoging we could be befoging you could be befoging they could be befoging
Perfect
I could have befoged you could have befoged she could have befoged we could have befoged you could have befoged they could have befoged
V-ing perfect
I could have been befoging you could have been befoging she could have been befoging we could have been befoging you could have been befoging they could have been befoging
Negation
Simple form
I couldn't befog you couldn't befog she couldn't befog we couldn't befog you couldn't befog they couldn't befog
V-ing form
I couldn't be befoging you couldn't be befoging she couldn't be befoging we couldn't be befoging you couldn't be befoging they couldn't be befoging
Perfect
I couldn't have befoged you couldn't have befoged she couldn't have befoged we couldn't have befoged you couldn't have befoged they couldn't have befoged
V-ing perfect
I couldn't have been befoging you couldn't have been befoging she couldn't have been befoging we couldn't have been befoging you couldn't have been befoging they couldn't have been befoging
Interrogative form
Simple form
could I befog? could you befog? could she befog? could we befog? could you befog? could they befog?
V-ing form
could I be befoging? could you be befoging? could she be befoging? could we be befoging? could you be befoging? could they be befoging?
Perfect
could I have befoged? could you have befoged? could she have befoged? could we have befoged? could you have befoged? could they have befoged?
V-ing perfect
could I have been befoging? could you have been befoging? could she have been befoging? could we have been befoging? could you have been befoging? could they have been befoging?
Interro-negative form
Simple form
couldn't I befog? couldn't you befog? couldn't she befog? couldn't we befog? couldn't you befog? couldn't they befog?
V-ing form
couldn't I be befoging? couldn't you be befoging? couldn't she be befoging? couldn't we be befoging? couldn't you be befoging? couldn't they be befoging?
Perfect
couldn't I have befoged? couldn't you have befoged? couldn't she have befoged? couldn't we have befoged? couldn't you have befoged? couldn't they have befoged?
V-ing perfect
couldn't I have been befoging? couldn't you have been befoging? couldn't she have been befoging? couldn't we have been befoging? couldn't you have been befoging? couldn't they have been befoging?