I can prefocus you can prefocus he can prefocus we can prefocus you can prefocus they can prefocus
V-ing form
I can be prefocusing you can be prefocusing he can be prefocusing we can be prefocusing you can be prefocusing they can be prefocusing
Perfect
I can have prefocused you can have prefocused he can have prefocused we can have prefocused you can have prefocused they can have prefocused
V-ing perfect
I can have been prefocusing you can have been prefocusing he can have been prefocusing we can have been prefocusing you can have been prefocusing they can have been prefocusing
Negation
Simple form
I cannot prefocus you cannot prefocus he cannot prefocus we cannot prefocus you cannot prefocus they cannot prefocus
V-ing form
I cannot be prefocusing you cannot be prefocusing he cannot be prefocusing we cannot be prefocusing you cannot be prefocusing they cannot be prefocusing
Perfect
I cannot have prefocused you cannot have prefocused he cannot have prefocused we cannot have prefocused you cannot have prefocused they cannot have prefocused
V-ing perfect
I cannot have been prefocusing you cannot have been prefocusing he cannot have been prefocusing we cannot have been prefocusing you cannot have been prefocusing they cannot have been prefocusing
Interrogative form
Simple form
can I prefocus? can you prefocus? can he prefocus? can we prefocus? can you prefocus? can they prefocus?
V-ing form
can I be prefocusing? can you be prefocusing? can he be prefocusing? can we be prefocusing? can you be prefocusing? can they be prefocusing?
Perfect
can I have prefocused? can you have prefocused? can he have prefocused? can we have prefocused? can you have prefocused? can they have prefocused?
V-ing perfect
can I have been prefocusing? can you have been prefocusing? can he have been prefocusing? can we have been prefocusing? can you have been prefocusing? can they have been prefocusing?
Interro-negative form
Simple form
can I not prefocus? can you not prefocus? can he not prefocus? can we not prefocus? can you not prefocus? can they not prefocus?
V-ing form
can I not be prefocusing? can you not be prefocusing? can he not be prefocusing? can we not be prefocusing? can you not be prefocusing? can they not be prefocusing?
Perfect
can I not have prefocused? can you not have prefocused? can he not have prefocused? can we not have prefocused? can you not have prefocused? can they not have prefocused?
V-ing perfect
can I not have been prefocusing? can you not have been prefocusing? can he not have been prefocusing? can we not have been prefocusing? can you not have been prefocusing? can they not have been prefocusing?