I could owe you could owe she could owe we could owe you could owe they could owe
V-ing form
I could be owing you could be owing she could be owing we could be owing you could be owing they could be owing
Perfect
I could have owed you could have owed she could have owed we could have owed you could have owed they could have owed
V-ing perfect
I could have been owing you could have been owing she could have been owing we could have been owing you could have been owing they could have been owing
Negation
Simple form
I could not owe you could not owe she could not owe we could not owe you could not owe they could not owe
V-ing form
I could not be owing you could not be owing she could not be owing we could not be owing you could not be owing they could not be owing
Perfect
I could not have owed you could not have owed she could not have owed we could not have owed you could not have owed they could not have owed
V-ing perfect
I could not have been owing you could not have been owing she could not have been owing we could not have been owing you could not have been owing they could not have been owing
Interrogative form
Simple form
could I owe? could you owe? could she owe? could we owe? could you owe? could they owe?
V-ing form
could I be owing? could you be owing? could she be owing? could we be owing? could you be owing? could they be owing?
Perfect
could I have owed? could you have owed? could she have owed? could we have owed? could you have owed? could they have owed?
V-ing perfect
could I have been owing? could you have been owing? could she have been owing? could we have been owing? could you have been owing? could they have been owing?
Interro-negative form
Simple form
could I not owe? could you not owe? could she not owe? could we not owe? could you not owe? could they not owe?
V-ing form
could I not be owing? could you not be owing? could she not be owing? could we not be owing? could you not be owing? could they not be owing?
Perfect
could I not have owed? could you not have owed? could she not have owed? could we not have owed? could you not have owed? could they not have owed?
V-ing perfect
could I not have been owing? could you not have been owing? could she not have been owing? could we not have been owing? could you not have been owing? could they not have been owing?