I could sneer you could sneer he could sneer we could sneer you could sneer they could sneer
V-ing form
I could be sneering you could be sneering he could be sneering we could be sneering you could be sneering they could be sneering
Perfect
I could have sneered you could have sneered he could have sneered we could have sneered you could have sneered they could have sneered
V-ing perfect
I could have been sneering you could have been sneering he could have been sneering we could have been sneering you could have been sneering they could have been sneering
Negation
Simple form
I could not sneer you could not sneer he could not sneer we could not sneer you could not sneer they could not sneer
V-ing form
I could not be sneering you could not be sneering he could not be sneering we could not be sneering you could not be sneering they could not be sneering
Perfect
I could not have sneered you could not have sneered he could not have sneered we could not have sneered you could not have sneered they could not have sneered
V-ing perfect
I could not have been sneering you could not have been sneering he could not have been sneering we could not have been sneering you could not have been sneering they could not have been sneering
Interrogative form
Simple form
could I sneer? could you sneer? could he sneer? could we sneer? could you sneer? could they sneer?
V-ing form
could I be sneering? could you be sneering? could he be sneering? could we be sneering? could you be sneering? could they be sneering?
Perfect
could I have sneered? could you have sneered? could he have sneered? could we have sneered? could you have sneered? could they have sneered?
V-ing perfect
could I have been sneering? could you have been sneering? could he have been sneering? could we have been sneering? could you have been sneering? could they have been sneering?
Interro-negative form
Simple form
could I not sneer? could you not sneer? could he not sneer? could we not sneer? could you not sneer? could they not sneer?
V-ing form
could I not be sneering? could you not be sneering? could he not be sneering? could we not be sneering? could you not be sneering? could they not be sneering?
Perfect
could I not have sneered? could you not have sneered? could he not have sneered? could we not have sneered? could you not have sneered? could they not have sneered?
V-ing perfect
could I not have been sneering? could you not have been sneering? could he not have been sneering? could we not have been sneering? could you not have been sneering? could they not have been sneering?