I could fringe you could fringe he could fringe we could fringe you could fringe they could fringe
V-ing form
I could be fringing you could be fringing he could be fringing we could be fringing you could be fringing they could be fringing
Perfect
I could have fringed you could have fringed he could have fringed we could have fringed you could have fringed they could have fringed
V-ing perfect
I could have been fringing you could have been fringing he could have been fringing we could have been fringing you could have been fringing they could have been fringing
Negation
Simple form
I couldn't fringe you couldn't fringe he couldn't fringe we couldn't fringe you couldn't fringe they couldn't fringe
V-ing form
I couldn't be fringing you couldn't be fringing he couldn't be fringing we couldn't be fringing you couldn't be fringing they couldn't be fringing
Perfect
I couldn't have fringed you couldn't have fringed he couldn't have fringed we couldn't have fringed you couldn't have fringed they couldn't have fringed
V-ing perfect
I couldn't have been fringing you couldn't have been fringing he couldn't have been fringing we couldn't have been fringing you couldn't have been fringing they couldn't have been fringing
Interrogative form
Simple form
could I fringe? could you fringe? could he fringe? could we fringe? could you fringe? could they fringe?
V-ing form
could I be fringing? could you be fringing? could he be fringing? could we be fringing? could you be fringing? could they be fringing?
Perfect
could I have fringed? could you have fringed? could he have fringed? could we have fringed? could you have fringed? could they have fringed?
V-ing perfect
could I have been fringing? could you have been fringing? could he have been fringing? could we have been fringing? could you have been fringing? could they have been fringing?
Interro-negative form
Simple form
couldn't I fringe? couldn't you fringe? couldn't he fringe? couldn't we fringe? couldn't you fringe? couldn't they fringe?
V-ing form
couldn't I be fringing? couldn't you be fringing? couldn't he be fringing? couldn't we be fringing? couldn't you be fringing? couldn't they be fringing?
Perfect
couldn't I have fringed? couldn't you have fringed? couldn't he have fringed? couldn't we have fringed? couldn't you have fringed? couldn't they have fringed?
V-ing perfect
couldn't I have been fringing? couldn't you have been fringing? couldn't he have been fringing? couldn't we have been fringing? couldn't you have been fringing? couldn't they have been fringing?