English verb conjugation
COULD REFERENCE

Regular verb: reference - referenced - referenced

Affirmation

Simple form	V-ing form
I could reference you could reference he could reference we could reference you could reference they could reference	I could be referencing you could be referencing he could be referencing we could be referencing you could be referencing they could be referencing
Perfect	V-ing perfect
I could have referenced you could have referenced he could have referenced we could have referenced you could have referenced they could have referenced	I could have been referencing you could have been referencing he could have been referencing we could have been referencing you could have been referencing they could have been referencing

Negation

Simple form	V-ing form
I couldn't reference you couldn't reference he couldn't reference we couldn't reference you couldn't reference they couldn't reference	I couldn't be referencing you couldn't be referencing he couldn't be referencing we couldn't be referencing you couldn't be referencing they couldn't be referencing
Perfect	V-ing perfect
I couldn't have referenced you couldn't have referenced he couldn't have referenced we couldn't have referenced you couldn't have referenced they couldn't have referenced	I couldn't have been referencing you couldn't have been referencing he couldn't have been referencing we couldn't have been referencing you couldn't have been referencing they couldn't have been referencing

Interrogative form

Simple form	V-ing form
could I reference? could you reference? could he reference? could we reference? could you reference? could they reference?	could I be referencing? could you be referencing? could he be referencing? could we be referencing? could you be referencing? could they be referencing?
Perfect	V-ing perfect
could I have referenced? could you have referenced? could he have referenced? could we have referenced? could you have referenced? could they have referenced?	could I have been referencing? could you have been referencing? could he have been referencing? could we have been referencing? could you have been referencing? could they have been referencing?

Interro-negative form

Simple form	V-ing form
couldn't I reference? couldn't you reference? couldn't he reference? couldn't we reference? couldn't you reference? couldn't they reference?	couldn't I be referencing? couldn't you be referencing? couldn't he be referencing? couldn't we be referencing? couldn't you be referencing? couldn't they be referencing?
Perfect	V-ing perfect
couldn't I have referenced? couldn't you have referenced? couldn't he have referenced? couldn't we have referenced? couldn't you have referenced? couldn't they have referenced?	couldn't I have been referencing? couldn't you have been referencing? couldn't he have been referencing? couldn't we have been referencing? couldn't you have been referencing? couldn't they have been referencing?