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 can't answer you can't answer she can't answer we can't answer you can't answer they can't answer
V-ing form
I can't be answering you can't be answering she can't be answering we can't be answering you can't be answering they can't be answering
Perfect
I can't have answered you can't have answered she can't have answered we can't have answered you can't have answered they can't have answered
V-ing perfect
I can't have been answering you can't have been answering she can't have been answering we can't have been answering you can't have been answering they can't 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't I answer? can't you answer? can't she answer? can't we answer? can't you answer? can't they answer?
V-ing form
can't I be answering? can't you be answering? can't she be answering? can't we be answering? can't you be answering? can't they be answering?
Perfect
can't I have answered? can't you have answered? can't she have answered? can't we have answered? can't you have answered? can't they have answered?
V-ing perfect
can't I have been answering? can't you have been answering? can't she have been answering? can't we have been answering? can't you have been answering? can't they have been answering?