English verb conjugation
COULD OPEN

Regular verb: open - opened - opened

Affirmation

Simple form	V-ing form
I could open you could open she could open we could open you could open they could open	I could be opening you could be opening she could be opening we could be opening you could be opening they could be opening
Perfect	V-ing perfect
I could have opened you could have opened she could have opened we could have opened you could have opened they could have opened	I could have been opening you could have been opening she could have been opening we could have been opening you could have been opening they could have been opening

Negation

Simple form	V-ing form
I couldn't open you couldn't open she couldn't open we couldn't open you couldn't open they couldn't open	I couldn't be opening you couldn't be opening she couldn't be opening we couldn't be opening you couldn't be opening they couldn't be opening
Perfect	V-ing perfect
I couldn't have opened you couldn't have opened she couldn't have opened we couldn't have opened you couldn't have opened they couldn't have opened	I couldn't have been opening you couldn't have been opening she couldn't have been opening we couldn't have been opening you couldn't have been opening they couldn't have been opening

Interrogative form

Simple form	V-ing form
could I open? could you open? could she open? could we open? could you open? could they open?	could I be opening? could you be opening? could she be opening? could we be opening? could you be opening? could they be opening?
Perfect	V-ing perfect
could I have opened? could you have opened? could she have opened? could we have opened? could you have opened? could they have opened?	could I have been opening? could you have been opening? could she have been opening? could we have been opening? could you have been opening? could they have been opening?

Interro-negative form

Simple form	V-ing form
couldn't I open? couldn't you open? couldn't she open? couldn't we open? couldn't you open? couldn't they open?	couldn't I be opening? couldn't you be opening? couldn't she be opening? couldn't we be opening? couldn't you be opening? couldn't they be opening?
Perfect	V-ing perfect
couldn't I have opened? couldn't you have opened? couldn't she have opened? couldn't we have opened? couldn't you have opened? couldn't they have opened?	couldn't I have been opening? couldn't you have been opening? couldn't she have been opening? couldn't we have been opening? couldn't you have been opening? couldn't they have been opening?