I can buffer you can buffer he can buffer we can buffer you can buffer they can buffer
V-ing form
I can be buffering you can be buffering he can be buffering we can be buffering you can be buffering they can be buffering
Perfect
I can have buffered you can have buffered he can have buffered we can have buffered you can have buffered they can have buffered
V-ing perfect
I can have been buffering you can have been buffering he can have been buffering we can have been buffering you can have been buffering they can have been buffering
Negation
Simple form
I cannot buffer you cannot buffer he cannot buffer we cannot buffer you cannot buffer they cannot buffer
V-ing form
I cannot be buffering you cannot be buffering he cannot be buffering we cannot be buffering you cannot be buffering they cannot be buffering
Perfect
I cannot have buffered you cannot have buffered he cannot have buffered we cannot have buffered you cannot have buffered they cannot have buffered
V-ing perfect
I cannot have been buffering you cannot have been buffering he cannot have been buffering we cannot have been buffering you cannot have been buffering they cannot have been buffering
Interrogative form
Simple form
can I buffer? can you buffer? can he buffer? can we buffer? can you buffer? can they buffer?
V-ing form
can I be buffering? can you be buffering? can he be buffering? can we be buffering? can you be buffering? can they be buffering?
Perfect
can I have buffered? can you have buffered? can he have buffered? can we have buffered? can you have buffered? can they have buffered?
V-ing perfect
can I have been buffering? can you have been buffering? can he have been buffering? can we have been buffering? can you have been buffering? can they have been buffering?
Interro-negative form
Simple form
can I not buffer? can you not buffer? can he not buffer? can we not buffer? can you not buffer? can they not buffer?
V-ing form
can I not be buffering? can you not be buffering? can he not be buffering? can we not be buffering? can you not be buffering? can they not be buffering?
Perfect
can I not have buffered? can you not have buffered? can he not have buffered? can we not have buffered? can you not have buffered? can they not have buffered?
V-ing perfect
can I not have been buffering? can you not have been buffering? can he not have been buffering? can we not have been buffering? can you not have been buffering? can they not have been buffering?