I can answer you can answer she can answer we can answer you can answer they can answer
V-ing form
I can be answering you can be answering she can be answering we can be answering you can be answering they can be answering
Perfect
I can have answered you can have answered she can have answered we can have answered you can have answered they can have answered
V-ing perfect
I can have been answering you can have been answering she can have been answering we can have been answering you can have been answering they can have been answering
Negation
Simple form
I cannot answer you cannot answer she cannot answer we cannot answer you cannot answer they cannot answer
V-ing form
I cannot be answering you cannot be answering she cannot be answering we cannot be answering you cannot be answering they cannot be answering
Perfect
I cannot have answered you cannot have answered she cannot have answered we cannot have answered you cannot have answered they cannot have answered
V-ing perfect
I cannot have been answering you cannot have been answering she cannot have been answering we cannot have been answering you cannot have been answering they cannot have been answering
Interrogative form
Simple form
can I answer? can you answer? can she answer? can we answer? can you answer? can they answer?
V-ing form
can I be answering? can you be answering? can she be answering? can we be answering? can you be answering? can they be answering?
Perfect
can I have answered? can you have answered? can she have answered? can we have answered? can you have answered? can they have answered?
V-ing perfect
can I have been answering? can you have been answering? can she have been answering? can we have been answering? can you have been answering? can they have been answering?
Interro-negative form
Simple form
can I not answer? can you not answer? can she not answer? can we not answer? can you not answer? can they not answer?
V-ing form
can I not be answering? can you not be answering? can she not be answering? can we not be answering? can you not be answering? can they not be answering?
Perfect
can I not have answered? can you not have answered? can she not have answered? can we not have answered? can you not have answered? can they not have answered?
V-ing perfect
can I not have been answering? can you not have been answering? can she not have been answering? can we not have been answering? can you not have been answering? can they not have been answering?