I can follow you can follow he can follow we can follow you can follow they can follow
V-ing form
I can be following you can be following he can be following we can be following you can be following they can be following
Perfect
I can have followed you can have followed he can have followed we can have followed you can have followed they can have followed
V-ing perfect
I can have been following you can have been following he can have been following we can have been following you can have been following they can have been following
Negation
Simple form
I cannot follow you cannot follow he cannot follow we cannot follow you cannot follow they cannot follow
V-ing form
I cannot be following you cannot be following he cannot be following we cannot be following you cannot be following they cannot be following
Perfect
I cannot have followed you cannot have followed he cannot have followed we cannot have followed you cannot have followed they cannot have followed
V-ing perfect
I cannot have been following you cannot have been following he cannot have been following we cannot have been following you cannot have been following they cannot have been following
Interrogative form
Simple form
can I follow? can you follow? can he follow? can we follow? can you follow? can they follow?
V-ing form
can I be following? can you be following? can he be following? can we be following? can you be following? can they be following?
Perfect
can I have followed? can you have followed? can he have followed? can we have followed? can you have followed? can they have followed?
V-ing perfect
can I have been following? can you have been following? can he have been following? can we have been following? can you have been following? can they have been following?
Interro-negative form
Simple form
can I not follow? can you not follow? can he not follow? can we not follow? can you not follow? can they not follow?
V-ing form
can I not be following? can you not be following? can he not be following? can we not be following? can you not be following? can they not be following?
Perfect
can I not have followed? can you not have followed? can he not have followed? can we not have followed? can you not have followed? can they not have followed?
V-ing perfect
can I not have been following? can you not have been following? can he not have been following? can we not have been following? can you not have been following? can they not have been following?