I can post you can post he can post we can post you can post they can post
V-ing form
I can be posting you can be posting he can be posting we can be posting you can be posting they can be posting
Perfect
I can have posted you can have posted he 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 he 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 he cannot post we cannot post you cannot post they cannot post
V-ing form
I cannot be posting you cannot be posting he cannot be posting we cannot be posting you cannot be posting they cannot be posting
Perfect
I cannot have posted you cannot have posted he 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 he 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 he post? can we post? can you post? can they post?
V-ing form
can I be posting? can you be posting? can he be posting? can we be posting? can you be posting? can they be posting?
Perfect
can I have posted? can you have posted? can he 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 he 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 he 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 he 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 he 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 he not have been posting? can we not have been posting? can you not have been posting? can they not have been posting?