I can let you can let she can let we can let you can let they can let
V-ing form
I can be letting you can be letting she can be letting we can be letting you can be letting they can be letting
Perfect
I can have let you can have let she can have let we can have let you can have let they can have let
V-ing perfect
I can have been letting you can have been letting she can have been letting we can have been letting you can have been letting they can have been letting
Negation
Simple form
I can't let you can't let she can't let we can't let you can't let they can't let
V-ing form
I can't be letting you can't be letting she can't be letting we can't be letting you can't be letting they can't be letting
Perfect
I can't have let you can't have let she can't have let we can't have let you can't have let they can't have let
V-ing perfect
I can't have been letting you can't have been letting she can't have been letting we can't have been letting you can't have been letting they can't have been letting
Interrogative form
Simple form
can I let? can you let? can she let? can we let? can you let? can they let?
V-ing form
can I be letting? can you be letting? can she be letting? can we be letting? can you be letting? can they be letting?
Perfect
can I have let? can you have let? can she have let? can we have let? can you have let? can they have let?
V-ing perfect
can I have been letting? can you have been letting? can she have been letting? can we have been letting? can you have been letting? can they have been letting?
Interro-negative form
Simple form
can't I let? can't you let? can't she let? can't we let? can't you let? can't they let?
V-ing form
can't I be letting? can't you be letting? can't she be letting? can't we be letting? can't you be letting? can't they be letting?
Perfect
can't I have let? can't you have let? can't she have let? can't we have let? can't you have let? can't they have let?
V-ing perfect
can't I have been letting? can't you have been letting? can't she have been letting? can't we have been letting? can't you have been letting? can't they have been letting?