I can fox you can fox he can fox we can fox you can fox they can fox
V-ing form
I can be foxing you can be foxing he can be foxing we can be foxing you can be foxing they can be foxing
Perfect
I can have foxed you can have foxed he can have foxed we can have foxed you can have foxed they can have foxed
V-ing perfect
I can have been foxing you can have been foxing he can have been foxing we can have been foxing you can have been foxing they can have been foxing
Negation
Simple form
I cannot fox you cannot fox he cannot fox we cannot fox you cannot fox they cannot fox
V-ing form
I cannot be foxing you cannot be foxing he cannot be foxing we cannot be foxing you cannot be foxing they cannot be foxing
Perfect
I cannot have foxed you cannot have foxed he cannot have foxed we cannot have foxed you cannot have foxed they cannot have foxed
V-ing perfect
I cannot have been foxing you cannot have been foxing he cannot have been foxing we cannot have been foxing you cannot have been foxing they cannot have been foxing
Interrogative form
Simple form
can I fox? can you fox? can he fox? can we fox? can you fox? can they fox?
V-ing form
can I be foxing? can you be foxing? can he be foxing? can we be foxing? can you be foxing? can they be foxing?
Perfect
can I have foxed? can you have foxed? can he have foxed? can we have foxed? can you have foxed? can they have foxed?
V-ing perfect
can I have been foxing? can you have been foxing? can he have been foxing? can we have been foxing? can you have been foxing? can they have been foxing?
Interro-negative form
Simple form
can I not fox? can you not fox? can he not fox? can we not fox? can you not fox? can they not fox?
V-ing form
can I not be foxing? can you not be foxing? can he not be foxing? can we not be foxing? can you not be foxing? can they not be foxing?
Perfect
can I not have foxed? can you not have foxed? can he not have foxed? can we not have foxed? can you not have foxed? can they not have foxed?
V-ing perfect
can I not have been foxing? can you not have been foxing? can he not have been foxing? can we not have been foxing? can you not have been foxing? can they not have been foxing?