I can mail you can mail she can mail we can mail you can mail they can mail
V-ing form
I can be mailing you can be mailing she can be mailing we can be mailing you can be mailing they can be mailing
Perfect
I can have mailed you can have mailed she can have mailed we can have mailed you can have mailed they can have mailed
V-ing perfect
I can have been mailing you can have been mailing she can have been mailing we can have been mailing you can have been mailing they can have been mailing
Negation
Simple form
I can't mail you can't mail she can't mail we can't mail you can't mail they can't mail
V-ing form
I can't be mailing you can't be mailing she can't be mailing we can't be mailing you can't be mailing they can't be mailing
Perfect
I can't have mailed you can't have mailed she can't have mailed we can't have mailed you can't have mailed they can't have mailed
V-ing perfect
I can't have been mailing you can't have been mailing she can't have been mailing we can't have been mailing you can't have been mailing they can't have been mailing
Interrogative form
Simple form
can I mail? can you mail? can she mail? can we mail? can you mail? can they mail?
V-ing form
can I be mailing? can you be mailing? can she be mailing? can we be mailing? can you be mailing? can they be mailing?
Perfect
can I have mailed? can you have mailed? can she have mailed? can we have mailed? can you have mailed? can they have mailed?
V-ing perfect
can I have been mailing? can you have been mailing? can she have been mailing? can we have been mailing? can you have been mailing? can they have been mailing?
Interro-negative form
Simple form
can't I mail? can't you mail? can't she mail? can't we mail? can't you mail? can't they mail?
V-ing form
can't I be mailing? can't you be mailing? can't she be mailing? can't we be mailing? can't you be mailing? can't they be mailing?
Perfect
can't I have mailed? can't you have mailed? can't she have mailed? can't we have mailed? can't you have mailed? can't they have mailed?
V-ing perfect
can't I have been mailing? can't you have been mailing? can't she have been mailing? can't we have been mailing? can't you have been mailing? can't they have been mailing?