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