I can birl you can birl he can birl we can birl you can birl they can birl
V-ing form
I can be birling you can be birling he can be birling we can be birling you can be birling they can be birling
Perfect
I can have birled you can have birled he can have birled we can have birled you can have birled they can have birled
V-ing perfect
I can have been birling you can have been birling he can have been birling we can have been birling you can have been birling they can have been birling
Negation
Simple form
I cannot birl you cannot birl he cannot birl we cannot birl you cannot birl they cannot birl
V-ing form
I cannot be birling you cannot be birling he cannot be birling we cannot be birling you cannot be birling they cannot be birling
Perfect
I cannot have birled you cannot have birled he cannot have birled we cannot have birled you cannot have birled they cannot have birled
V-ing perfect
I cannot have been birling you cannot have been birling he cannot have been birling we cannot have been birling you cannot have been birling they cannot have been birling
Interrogative form
Simple form
can I birl? can you birl? can he birl? can we birl? can you birl? can they birl?
V-ing form
can I be birling? can you be birling? can he be birling? can we be birling? can you be birling? can they be birling?
Perfect
can I have birled? can you have birled? can he have birled? can we have birled? can you have birled? can they have birled?
V-ing perfect
can I have been birling? can you have been birling? can he have been birling? can we have been birling? can you have been birling? can they have been birling?
Interro-negative form
Simple form
can I not birl? can you not birl? can he not birl? can we not birl? can you not birl? can they not birl?
V-ing form
can I not be birling? can you not be birling? can he not be birling? can we not be birling? can you not be birling? can they not be birling?
Perfect
can I not have birled? can you not have birled? can he not have birled? can we not have birled? can you not have birled? can they not have birled?
V-ing perfect
can I not have been birling? can you not have been birling? can he not have been birling? can we not have been birling? can you not have been birling? can they not have been birling?