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