English verb conjugation
COULD EXTRACT

Regular verb: extract - extracted - extracted

Affirmation

Simple form	V-ing form
I could extract you could extract he could extract we could extract you could extract they could extract	I could be extracting you could be extracting he could be extracting we could be extracting you could be extracting they could be extracting
Perfect	V-ing perfect
I could have extracted you could have extracted he could have extracted we could have extracted you could have extracted they could have extracted	I could have been extracting you could have been extracting he could have been extracting we could have been extracting you could have been extracting they could have been extracting

Negation

Simple form	V-ing form
I could not extract you could not extract he could not extract we could not extract you could not extract they could not extract	I could not be extracting you could not be extracting he could not be extracting we could not be extracting you could not be extracting they could not be extracting
Perfect	V-ing perfect
I could not have extracted you could not have extracted he could not have extracted we could not have extracted you could not have extracted they could not have extracted	I could not have been extracting you could not have been extracting he could not have been extracting we could not have been extracting you could not have been extracting they could not have been extracting

Interrogative form

Simple form	V-ing form
could I extract? could you extract? could he extract? could we extract? could you extract? could they extract?	could I be extracting? could you be extracting? could he be extracting? could we be extracting? could you be extracting? could they be extracting?
Perfect	V-ing perfect
could I have extracted? could you have extracted? could he have extracted? could we have extracted? could you have extracted? could they have extracted?	could I have been extracting? could you have been extracting? could he have been extracting? could we have been extracting? could you have been extracting? could they have been extracting?

Interro-negative form

Simple form	V-ing form
could I not extract? could you not extract? could he not extract? could we not extract? could you not extract? could they not extract?	could I not be extracting? could you not be extracting? could he not be extracting? could we not be extracting? could you not be extracting? could they not be extracting?
Perfect	V-ing perfect
could I not have extracted? could you not have extracted? could he not have extracted? could we not have extracted? could you not have extracted? could they not have extracted?	could I not have been extracting? could you not have been extracting? could he not have been extracting? could we not have been extracting? could you not have been extracting? could they not have been extracting?