I can post you can post she can post we can post you can post they can post
V-ing form
I can be posting you can be posting she can be posting we can be posting you can be posting they can be posting
Perfect
I can have posted you can have posted she can have posted we can have posted you can have posted they can have posted
V-ing perfect
I can have been posting you can have been posting she can have been posting we can have been posting you can have been posting they can have been posting
Negation
Simple form
I cannot post you cannot post she cannot post we cannot post you cannot post they cannot post
V-ing form
I cannot be posting you cannot be posting she cannot be posting we cannot be posting you cannot be posting they cannot be posting
Perfect
I cannot have posted you cannot have posted she cannot have posted we cannot have posted you cannot have posted they cannot have posted
V-ing perfect
I cannot have been posting you cannot have been posting she cannot have been posting we cannot have been posting you cannot have been posting they cannot have been posting
Interrogative form
Simple form
can I post? can you post? can she post? can we post? can you post? can they post?
V-ing form
can I be posting? can you be posting? can she be posting? can we be posting? can you be posting? can they be posting?
Perfect
can I have posted? can you have posted? can she have posted? can we have posted? can you have posted? can they have posted?
V-ing perfect
can I have been posting? can you have been posting? can she have been posting? can we have been posting? can you have been posting? can they have been posting?
Interro-negative form
Simple form
can I not post? can you not post? can she not post? can we not post? can you not post? can they not post?
V-ing form
can I not be posting? can you not be posting? can she not be posting? can we not be posting? can you not be posting? can they not be posting?
Perfect
can I not have posted? can you not have posted? can she not have posted? can we not have posted? can you not have posted? can they not have posted?
V-ing perfect
can I not have been posting? can you not have been posting? can she not have been posting? can we not have been posting? can you not have been posting? can they not have been posting?