English verb conjugation
COULD OPEN

Regular verb: open - opened - opened

Affirmation

Simple form	V-ing form
I could open you could open he could open we could open you could open they could open	I could be opening you could be opening he 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 he 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 he 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 could not open you could not open he could not open we could not open you could not open they could not open	I could not be opening you could not be opening he could not be opening we could not be opening you could not be opening they could not be opening
Perfect	V-ing perfect
I could not have opened you could not have opened he could not have opened we could not have opened you could not have opened they could not have opened	I could not have been opening you could not have been opening he could not have been opening we could not have been opening you could not have been opening they could not have been opening

Interrogative form

Simple form	V-ing form
could I open? could you open? could he open? could we open? could you open? could they open?	could I be opening? could you be opening? could he 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 he 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 he 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
could I not open? could you not open? could he not open? could we not open? could you not open? could they not open?	could I not be opening? could you not be opening? could he not be opening? could we not be opening? could you not be opening? could they not be opening?
Perfect	V-ing perfect
could I not have opened? could you not have opened? could he not have opened? could we not have opened? could you not have opened? could they not have opened?	could I not have been opening? could you not have been opening? could he not have been opening? could we not have been opening? could you not have been opening? could they not have been opening?