I can purr you can purr he can purr we can purr you can purr they can purr
V-ing form
I can be purring you can be purring he can be purring we can be purring you can be purring they can be purring
Perfect
I can have purred you can have purred he can have purred we can have purred you can have purred they can have purred
V-ing perfect
I can have been purring you can have been purring he can have been purring we can have been purring you can have been purring they can have been purring
Negation
Simple form
I cannot purr you cannot purr he cannot purr we cannot purr you cannot purr they cannot purr
V-ing form
I cannot be purring you cannot be purring he cannot be purring we cannot be purring you cannot be purring they cannot be purring
Perfect
I cannot have purred you cannot have purred he cannot have purred we cannot have purred you cannot have purred they cannot have purred
V-ing perfect
I cannot have been purring you cannot have been purring he cannot have been purring we cannot have been purring you cannot have been purring they cannot have been purring
Interrogative form
Simple form
can I purr? can you purr? can he purr? can we purr? can you purr? can they purr?
V-ing form
can I be purring? can you be purring? can he be purring? can we be purring? can you be purring? can they be purring?
Perfect
can I have purred? can you have purred? can he have purred? can we have purred? can you have purred? can they have purred?
V-ing perfect
can I have been purring? can you have been purring? can he have been purring? can we have been purring? can you have been purring? can they have been purring?
Interro-negative form
Simple form
can I not purr? can you not purr? can he not purr? can we not purr? can you not purr? can they not purr?
V-ing form
can I not be purring? can you not be purring? can he not be purring? can we not be purring? can you not be purring? can they not be purring?
Perfect
can I not have purred? can you not have purred? can he not have purred? can we not have purred? can you not have purred? can they not have purred?
V-ing perfect
can I not have been purring? can you not have been purring? can he not have been purring? can we not have been purring? can you not have been purring? can they not have been purring?