I can loo you can loo he can loo we can loo you can loo they can loo
V-ing form
I can be looing you can be looing he can be looing we can be looing you can be looing they can be looing
Perfect
I can have looed you can have looed he can have looed we can have looed you can have looed they can have looed
V-ing perfect
I can have been looing you can have been looing he can have been looing we can have been looing you can have been looing they can have been looing
Negation
Simple form
I cannot loo you cannot loo he cannot loo we cannot loo you cannot loo they cannot loo
V-ing form
I cannot be looing you cannot be looing he cannot be looing we cannot be looing you cannot be looing they cannot be looing
Perfect
I cannot have looed you cannot have looed he cannot have looed we cannot have looed you cannot have looed they cannot have looed
V-ing perfect
I cannot have been looing you cannot have been looing he cannot have been looing we cannot have been looing you cannot have been looing they cannot have been looing
Interrogative form
Simple form
can I loo? can you loo? can he loo? can we loo? can you loo? can they loo?
V-ing form
can I be looing? can you be looing? can he be looing? can we be looing? can you be looing? can they be looing?
Perfect
can I have looed? can you have looed? can he have looed? can we have looed? can you have looed? can they have looed?
V-ing perfect
can I have been looing? can you have been looing? can he have been looing? can we have been looing? can you have been looing? can they have been looing?
Interro-negative form
Simple form
can I not loo? can you not loo? can he not loo? can we not loo? can you not loo? can they not loo?
V-ing form
can I not be looing? can you not be looing? can he not be looing? can we not be looing? can you not be looing? can they not be looing?
Perfect
can I not have looed? can you not have looed? can he not have looed? can we not have looed? can you not have looed? can they not have looed?
V-ing perfect
can I not have been looing? can you not have been looing? can he not have been looing? can we not have been looing? can you not have been looing? can they not have been looing?