I can reference you can reference he can reference we can reference you can reference they can reference
V-ing form
I can be referencing you can be referencing he can be referencing we can be referencing you can be referencing they can be referencing
Perfect
I can have referenced you can have referenced he can have referenced we can have referenced you can have referenced they can have referenced
V-ing perfect
I can have been referencing you can have been referencing he can have been referencing we can have been referencing you can have been referencing they can have been referencing
Negation
Simple form
I cannot reference you cannot reference he cannot reference we cannot reference you cannot reference they cannot reference
V-ing form
I cannot be referencing you cannot be referencing he cannot be referencing we cannot be referencing you cannot be referencing they cannot be referencing
Perfect
I cannot have referenced you cannot have referenced he cannot have referenced we cannot have referenced you cannot have referenced they cannot have referenced
V-ing perfect
I cannot have been referencing you cannot have been referencing he cannot have been referencing we cannot have been referencing you cannot have been referencing they cannot have been referencing
Interrogative form
Simple form
can I reference? can you reference? can he reference? can we reference? can you reference? can they reference?
V-ing form
can I be referencing? can you be referencing? can he be referencing? can we be referencing? can you be referencing? can they be referencing?
Perfect
can I have referenced? can you have referenced? can he have referenced? can we have referenced? can you have referenced? can they have referenced?
V-ing perfect
can I have been referencing? can you have been referencing? can he have been referencing? can we have been referencing? can you have been referencing? can they have been referencing?
Interro-negative form
Simple form
can I not reference? can you not reference? can he not reference? can we not reference? can you not reference? can they not reference?
V-ing form
can I not be referencing? can you not be referencing? can he not be referencing? can we not be referencing? can you not be referencing? can they not be referencing?
Perfect
can I not have referenced? can you not have referenced? can he not have referenced? can we not have referenced? can you not have referenced? can they not have referenced?
V-ing perfect
can I not have been referencing? can you not have been referencing? can he not have been referencing? can we not have been referencing? can you not have been referencing? can they not have been referencing?