I could scribble you could scribble he could scribble we could scribble you could scribble they could scribble
V-ing form
I could be scribbling you could be scribbling he could be scribbling we could be scribbling you could be scribbling they could be scribbling
Perfect
I could have scribbled you could have scribbled he could have scribbled we could have scribbled you could have scribbled they could have scribbled
V-ing perfect
I could have been scribbling you could have been scribbling he could have been scribbling we could have been scribbling you could have been scribbling they could have been scribbling
Negation
Simple form
I could not scribble you could not scribble he could not scribble we could not scribble you could not scribble they could not scribble
V-ing form
I could not be scribbling you could not be scribbling he could not be scribbling we could not be scribbling you could not be scribbling they could not be scribbling
Perfect
I could not have scribbled you could not have scribbled he could not have scribbled we could not have scribbled you could not have scribbled they could not have scribbled
V-ing perfect
I could not have been scribbling you could not have been scribbling he could not have been scribbling we could not have been scribbling you could not have been scribbling they could not have been scribbling
Interrogative form
Simple form
could I scribble? could you scribble? could he scribble? could we scribble? could you scribble? could they scribble?
V-ing form
could I be scribbling? could you be scribbling? could he be scribbling? could we be scribbling? could you be scribbling? could they be scribbling?
Perfect
could I have scribbled? could you have scribbled? could he have scribbled? could we have scribbled? could you have scribbled? could they have scribbled?
V-ing perfect
could I have been scribbling? could you have been scribbling? could he have been scribbling? could we have been scribbling? could you have been scribbling? could they have been scribbling?
Interro-negative form
Simple form
could I not scribble? could you not scribble? could he not scribble? could we not scribble? could you not scribble? could they not scribble?
V-ing form
could I not be scribbling? could you not be scribbling? could he not be scribbling? could we not be scribbling? could you not be scribbling? could they not be scribbling?
Perfect
could I not have scribbled? could you not have scribbled? could he not have scribbled? could we not have scribbled? could you not have scribbled? could they not have scribbled?
V-ing perfect
could I not have been scribbling? could you not have been scribbling? could he not have been scribbling? could we not have been scribbling? could you not have been scribbling? could they not have been scribbling?