English verb conjugation
COULD RESPOND

Regular verb: respond - responded - responded

Affirmation

Simple form	V-ing form
I could respond you could respond he could respond we could respond you could respond they could respond	I could be responding you could be responding he could be responding we could be responding you could be responding they could be responding
Perfect	V-ing perfect
I could have responded you could have responded he could have responded we could have responded you could have responded they could have responded	I could have been responding you could have been responding he could have been responding we could have been responding you could have been responding they could have been responding

Negation

Simple form	V-ing form
I couldn't respond you couldn't respond he couldn't respond we couldn't respond you couldn't respond they couldn't respond	I couldn't be responding you couldn't be responding he couldn't be responding we couldn't be responding you couldn't be responding they couldn't be responding
Perfect	V-ing perfect
I couldn't have responded you couldn't have responded he couldn't have responded we couldn't have responded you couldn't have responded they couldn't have responded	I couldn't have been responding you couldn't have been responding he couldn't have been responding we couldn't have been responding you couldn't have been responding they couldn't have been responding

Interrogative form

Simple form	V-ing form
could I respond? could you respond? could he respond? could we respond? could you respond? could they respond?	could I be responding? could you be responding? could he be responding? could we be responding? could you be responding? could they be responding?
Perfect	V-ing perfect
could I have responded? could you have responded? could he have responded? could we have responded? could you have responded? could they have responded?	could I have been responding? could you have been responding? could he have been responding? could we have been responding? could you have been responding? could they have been responding?

Interro-negative form

Simple form	V-ing form
couldn't I respond? couldn't you respond? couldn't he respond? couldn't we respond? couldn't you respond? couldn't they respond?	couldn't I be responding? couldn't you be responding? couldn't he be responding? couldn't we be responding? couldn't you be responding? couldn't they be responding?
Perfect	V-ing perfect
couldn't I have responded? couldn't you have responded? couldn't he have responded? couldn't we have responded? couldn't you have responded? couldn't they have responded?	couldn't I have been responding? couldn't you have been responding? couldn't he have been responding? couldn't we have been responding? couldn't you have been responding? couldn't they have been responding?