I can pen you can pen he can pen we can pen you can pen they can pen
V-ing form
I can be penning you can be penning he can be penning we can be penning you can be penning they can be penning
Perfect
I can have penned you can have penned he can have penned we can have penned you can have penned they can have penned
V-ing perfect
I can have been penning you can have been penning he can have been penning we can have been penning you can have been penning they can have been penning
Negation
Simple form
I can't pen you can't pen he can't pen we can't pen you can't pen they can't pen
V-ing form
I can't be penning you can't be penning he can't be penning we can't be penning you can't be penning they can't be penning
Perfect
I can't have penned you can't have penned he can't have penned we can't have penned you can't have penned they can't have penned
V-ing perfect
I can't have been penning you can't have been penning he can't have been penning we can't have been penning you can't have been penning they can't have been penning
Interrogative form
Simple form
can I pen? can you pen? can he pen? can we pen? can you pen? can they pen?
V-ing form
can I be penning? can you be penning? can he be penning? can we be penning? can you be penning? can they be penning?
Perfect
can I have penned? can you have penned? can he have penned? can we have penned? can you have penned? can they have penned?
V-ing perfect
can I have been penning? can you have been penning? can he have been penning? can we have been penning? can you have been penning? can they have been penning?
Interro-negative form
Simple form
can't I pen? can't you pen? can't he pen? can't we pen? can't you pen? can't they pen?
V-ing form
can't I be penning? can't you be penning? can't he be penning? can't we be penning? can't you be penning? can't they be penning?
Perfect
can't I have penned? can't you have penned? can't he have penned? can't we have penned? can't you have penned? can't they have penned?
V-ing perfect
can't I have been penning? can't you have been penning? can't he have been penning? can't we have been penning? can't you have been penning? can't they have been penning?