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 can't follow you can't follow he can't follow we can't follow you can't follow they can't follow
V-ing form
I can't be following you can't be following he can't be following we can't be following you can't be following they can't be following
Perfect
I can't have followed you can't have followed he can't have followed we can't have followed you can't have followed they can't have followed
V-ing perfect
I can't have been following you can't have been following he can't have been following we can't have been following you can't have been following they can't 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't I follow? can't you follow? can't he follow? can't we follow? can't you follow? can't they follow?
V-ing form
can't I be following? can't you be following? can't he be following? can't we be following? can't you be following? can't they be following?
Perfect
can't I have followed? can't you have followed? can't he have followed? can't we have followed? can't you have followed? can't they have followed?
V-ing perfect
can't I have been following? can't you have been following? can't he have been following? can't we have been following? can't you have been following? can't they have been following?