English verb conjugation
COULD EXTRACT

Regular verb: extract - extracted - extracted

Affirmation

Simple form	V-ing form
I could extract you could extract she could extract we could extract you could extract they could extract	I could be extracting you could be extracting she 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 she 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 she 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 couldn't extract you couldn't extract she couldn't extract we couldn't extract you couldn't extract they couldn't extract	I couldn't be extracting you couldn't be extracting she couldn't be extracting we couldn't be extracting you couldn't be extracting they couldn't be extracting
Perfect	V-ing perfect
I couldn't have extracted you couldn't have extracted she couldn't have extracted we couldn't have extracted you couldn't have extracted they couldn't have extracted	I couldn't have been extracting you couldn't have been extracting she couldn't have been extracting we couldn't have been extracting you couldn't have been extracting they couldn't have been extracting

Interrogative form

Simple form	V-ing form
could I extract? could you extract? could she extract? could we extract? could you extract? could they extract?	could I be extracting? could you be extracting? could she 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 she 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 she 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
couldn't I extract? couldn't you extract? couldn't she extract? couldn't we extract? couldn't you extract? couldn't they extract?	couldn't I be extracting? couldn't you be extracting? couldn't she be extracting? couldn't we be extracting? couldn't you be extracting? couldn't they be extracting?
Perfect	V-ing perfect
couldn't I have extracted? couldn't you have extracted? couldn't she have extracted? couldn't we have extracted? couldn't you have extracted? couldn't they have extracted?	couldn't I have been extracting? couldn't you have been extracting? couldn't she have been extracting? couldn't we have been extracting? couldn't you have been extracting? couldn't they have been extracting?