English verb conjugation
COULD RIPEN

Regular verb: ripen - ripened - ripened

Affirmation

Simple form	V-ing form
I could ripen you could ripen he could ripen we could ripen you could ripen they could ripen	I could be ripening you could be ripening he could be ripening we could be ripening you could be ripening they could be ripening
Perfect	V-ing perfect
I could have ripened you could have ripened he could have ripened we could have ripened you could have ripened they could have ripened	I could have been ripening you could have been ripening he could have been ripening we could have been ripening you could have been ripening they could have been ripening

Negation

Simple form	V-ing form
I could not ripen you could not ripen he could not ripen we could not ripen you could not ripen they could not ripen	I could not be ripening you could not be ripening he could not be ripening we could not be ripening you could not be ripening they could not be ripening
Perfect	V-ing perfect
I could not have ripened you could not have ripened he could not have ripened we could not have ripened you could not have ripened they could not have ripened	I could not have been ripening you could not have been ripening he could not have been ripening we could not have been ripening you could not have been ripening they could not have been ripening

Interrogative form

Simple form	V-ing form
could I ripen? could you ripen? could he ripen? could we ripen? could you ripen? could they ripen?	could I be ripening? could you be ripening? could he be ripening? could we be ripening? could you be ripening? could they be ripening?
Perfect	V-ing perfect
could I have ripened? could you have ripened? could he have ripened? could we have ripened? could you have ripened? could they have ripened?	could I have been ripening? could you have been ripening? could he have been ripening? could we have been ripening? could you have been ripening? could they have been ripening?

Interro-negative form

Simple form	V-ing form
could I not ripen? could you not ripen? could he not ripen? could we not ripen? could you not ripen? could they not ripen?	could I not be ripening? could you not be ripening? could he not be ripening? could we not be ripening? could you not be ripening? could they not be ripening?
Perfect	V-ing perfect
could I not have ripened? could you not have ripened? could he not have ripened? could we not have ripened? could you not have ripened? could they not have ripened?	could I not have been ripening? could you not have been ripening? could he not have been ripening? could we not have been ripening? could you not have been ripening? could they not have been ripening?