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