English verb conjugation
COULD ATTACH

Regular verb: attach - attached - attached

Affirmation

Simple form	V-ing form
I could attach you could attach he could attach we could attach you could attach they could attach	I could be attaching you could be attaching he could be attaching we could be attaching you could be attaching they could be attaching
Perfect	V-ing perfect
I could have attached you could have attached he could have attached we could have attached you could have attached they could have attached	I could have been attaching you could have been attaching he could have been attaching we could have been attaching you could have been attaching they could have been attaching

Negation

Simple form	V-ing form
I couldn't attach you couldn't attach he couldn't attach we couldn't attach you couldn't attach they couldn't attach	I couldn't be attaching you couldn't be attaching he couldn't be attaching we couldn't be attaching you couldn't be attaching they couldn't be attaching
Perfect	V-ing perfect
I couldn't have attached you couldn't have attached he couldn't have attached we couldn't have attached you couldn't have attached they couldn't have attached	I couldn't have been attaching you couldn't have been attaching he couldn't have been attaching we couldn't have been attaching you couldn't have been attaching they couldn't have been attaching

Interrogative form

Simple form	V-ing form
could I attach? could you attach? could he attach? could we attach? could you attach? could they attach?	could I be attaching? could you be attaching? could he be attaching? could we be attaching? could you be attaching? could they be attaching?
Perfect	V-ing perfect
could I have attached? could you have attached? could he have attached? could we have attached? could you have attached? could they have attached?	could I have been attaching? could you have been attaching? could he have been attaching? could we have been attaching? could you have been attaching? could they have been attaching?

Interro-negative form

Simple form	V-ing form
couldn't I attach? couldn't you attach? couldn't he attach? couldn't we attach? couldn't you attach? couldn't they attach?	couldn't I be attaching? couldn't you be attaching? couldn't he be attaching? couldn't we be attaching? couldn't you be attaching? couldn't they be attaching?
Perfect	V-ing perfect
couldn't I have attached? couldn't you have attached? couldn't he have attached? couldn't we have attached? couldn't you have attached? couldn't they have attached?	couldn't I have been attaching? couldn't you have been attaching? couldn't he have been attaching? couldn't we have been attaching? couldn't you have been attaching? couldn't they have been attaching?