I can telephone you can telephone he can telephone we can telephone you can telephone they can telephone
V-ing form
I can be telephoning you can be telephoning he can be telephoning we can be telephoning you can be telephoning they can be telephoning
Perfect
I can have telephoned you can have telephoned he can have telephoned we can have telephoned you can have telephoned they can have telephoned
V-ing perfect
I can have been telephoning you can have been telephoning he can have been telephoning we can have been telephoning you can have been telephoning they can have been telephoning
Negation
Simple form
I cannot telephone you cannot telephone he cannot telephone we cannot telephone you cannot telephone they cannot telephone
V-ing form
I cannot be telephoning you cannot be telephoning he cannot be telephoning we cannot be telephoning you cannot be telephoning they cannot be telephoning
Perfect
I cannot have telephoned you cannot have telephoned he cannot have telephoned we cannot have telephoned you cannot have telephoned they cannot have telephoned
V-ing perfect
I cannot have been telephoning you cannot have been telephoning he cannot have been telephoning we cannot have been telephoning you cannot have been telephoning they cannot have been telephoning
Interrogative form
Simple form
can I telephone? can you telephone? can he telephone? can we telephone? can you telephone? can they telephone?
V-ing form
can I be telephoning? can you be telephoning? can he be telephoning? can we be telephoning? can you be telephoning? can they be telephoning?
Perfect
can I have telephoned? can you have telephoned? can he have telephoned? can we have telephoned? can you have telephoned? can they have telephoned?
V-ing perfect
can I have been telephoning? can you have been telephoning? can he have been telephoning? can we have been telephoning? can you have been telephoning? can they have been telephoning?
Interro-negative form
Simple form
can I not telephone? can you not telephone? can he not telephone? can we not telephone? can you not telephone? can they not telephone?
V-ing form
can I not be telephoning? can you not be telephoning? can he not be telephoning? can we not be telephoning? can you not be telephoning? can they not be telephoning?
Perfect
can I not have telephoned? can you not have telephoned? can he not have telephoned? can we not have telephoned? can you not have telephoned? can they not have telephoned?
V-ing perfect
can I not have been telephoning? can you not have been telephoning? can he not have been telephoning? can we not have been telephoning? can you not have been telephoning? can they not have been telephoning?