I can woof you can woof she can woof we can woof you can woof they can woof
V-ing form
I can be woofing you can be woofing she can be woofing we can be woofing you can be woofing they can be woofing
Perfect
I can have woofed you can have woofed she can have woofed we can have woofed you can have woofed they can have woofed
V-ing perfect
I can have been woofing you can have been woofing she can have been woofing we can have been woofing you can have been woofing they can have been woofing
Negation
Simple form
I cannot woof you cannot woof she cannot woof we cannot woof you cannot woof they cannot woof
V-ing form
I cannot be woofing you cannot be woofing she cannot be woofing we cannot be woofing you cannot be woofing they cannot be woofing
Perfect
I cannot have woofed you cannot have woofed she cannot have woofed we cannot have woofed you cannot have woofed they cannot have woofed
V-ing perfect
I cannot have been woofing you cannot have been woofing she cannot have been woofing we cannot have been woofing you cannot have been woofing they cannot have been woofing
Interrogative form
Simple form
can I woof? can you woof? can she woof? can we woof? can you woof? can they woof?
V-ing form
can I be woofing? can you be woofing? can she be woofing? can we be woofing? can you be woofing? can they be woofing?
Perfect
can I have woofed? can you have woofed? can she have woofed? can we have woofed? can you have woofed? can they have woofed?
V-ing perfect
can I have been woofing? can you have been woofing? can she have been woofing? can we have been woofing? can you have been woofing? can they have been woofing?
Interro-negative form
Simple form
can I not woof? can you not woof? can she not woof? can we not woof? can you not woof? can they not woof?
V-ing form
can I not be woofing? can you not be woofing? can she not be woofing? can we not be woofing? can you not be woofing? can they not be woofing?
Perfect
can I not have woofed? can you not have woofed? can she not have woofed? can we not have woofed? can you not have woofed? can they not have woofed?
V-ing perfect
can I not have been woofing? can you not have been woofing? can she not have been woofing? can we not have been woofing? can you not have been woofing? can they not have been woofing?