I can respond you can respond he can respond we can respond you can respond they can respond
V-ing form
I can be responding you can be responding he can be responding we can be responding you can be responding they can be responding
Perfect
I can have responded you can have responded he can have responded we can have responded you can have responded they can have responded
V-ing perfect
I can have been responding you can have been responding he can have been responding we can have been responding you can have been responding they can have been responding
Negation
Simple form
I cannot respond you cannot respond he cannot respond we cannot respond you cannot respond they cannot respond
V-ing form
I cannot be responding you cannot be responding he cannot be responding we cannot be responding you cannot be responding they cannot be responding
Perfect
I cannot have responded you cannot have responded he cannot have responded we cannot have responded you cannot have responded they cannot have responded
V-ing perfect
I cannot have been responding you cannot have been responding he cannot have been responding we cannot have been responding you cannot have been responding they cannot have been responding
Interrogative form
Simple form
can I respond? can you respond? can he respond? can we respond? can you respond? can they respond?
V-ing form
can I be responding? can you be responding? can he be responding? can we be responding? can you be responding? can they be responding?
Perfect
can I have responded? can you have responded? can he have responded? can we have responded? can you have responded? can they have responded?
V-ing perfect
can I have been responding? can you have been responding? can he have been responding? can we have been responding? can you have been responding? can they have been responding?
Interro-negative form
Simple form
can I not respond? can you not respond? can he not respond? can we not respond? can you not respond? can they not respond?
V-ing form
can I not be responding? can you not be responding? can he not be responding? can we not be responding? can you not be responding? can they not be responding?
Perfect
can I not have responded? can you not have responded? can he not have responded? can we not have responded? can you not have responded? can they not have responded?
V-ing perfect
can I not have been responding? can you not have been responding? can he not have been responding? can we not have been responding? can you not have been responding? can they not have been responding?