I can ask you can ask she can ask we can ask you can ask they can ask
V-ing form
I can be asking you can be asking she can be asking we can be asking you can be asking they can be asking
Perfect
I can have asked you can have asked she can have asked we can have asked you can have asked they can have asked
V-ing perfect
I can have been asking you can have been asking she can have been asking we can have been asking you can have been asking they can have been asking
Negation
Simple form
I can't ask you can't ask she can't ask we can't ask you can't ask they can't ask
V-ing form
I can't be asking you can't be asking she can't be asking we can't be asking you can't be asking they can't be asking
Perfect
I can't have asked you can't have asked she can't have asked we can't have asked you can't have asked they can't have asked
V-ing perfect
I can't have been asking you can't have been asking she can't have been asking we can't have been asking you can't have been asking they can't have been asking
Interrogative form
Simple form
can I ask? can you ask? can she ask? can we ask? can you ask? can they ask?
V-ing form
can I be asking? can you be asking? can she be asking? can we be asking? can you be asking? can they be asking?
Perfect
can I have asked? can you have asked? can she have asked? can we have asked? can you have asked? can they have asked?
V-ing perfect
can I have been asking? can you have been asking? can she have been asking? can we have been asking? can you have been asking? can they have been asking?
Interro-negative form
Simple form
can't I ask? can't you ask? can't she ask? can't we ask? can't you ask? can't they ask?
V-ing form
can't I be asking? can't you be asking? can't she be asking? can't we be asking? can't you be asking? can't they be asking?
Perfect
can't I have asked? can't you have asked? can't she have asked? can't we have asked? can't you have asked? can't they have asked?
V-ing perfect
can't I have been asking? can't you have been asking? can't she have been asking? can't we have been asking? can't you have been asking? can't they have been asking?