English verb conjugation
COULD WALK

Regular verb: walk - walked - walked

Affirmation

Simple form	V-ing form
I could walk you could walk he could walk we could walk you could walk they could walk	I could be walking you could be walking he could be walking we could be walking you could be walking they could be walking
Perfect	V-ing perfect
I could have walked you could have walked he could have walked we could have walked you could have walked they could have walked	I could have been walking you could have been walking he could have been walking we could have been walking you could have been walking they could have been walking

Negation

Simple form	V-ing form
I could not walk you could not walk he could not walk we could not walk you could not walk they could not walk	I could not be walking you could not be walking he could not be walking we could not be walking you could not be walking they could not be walking
Perfect	V-ing perfect
I could not have walked you could not have walked he could not have walked we could not have walked you could not have walked they could not have walked	I could not have been walking you could not have been walking he could not have been walking we could not have been walking you could not have been walking they could not have been walking

Interrogative form

Simple form	V-ing form
could I walk? could you walk? could he walk? could we walk? could you walk? could they walk?	could I be walking? could you be walking? could he be walking? could we be walking? could you be walking? could they be walking?
Perfect	V-ing perfect
could I have walked? could you have walked? could he have walked? could we have walked? could you have walked? could they have walked?	could I have been walking? could you have been walking? could he have been walking? could we have been walking? could you have been walking? could they have been walking?

Interro-negative form

Simple form	V-ing form
could I not walk? could you not walk? could he not walk? could we not walk? could you not walk? could they not walk?	could I not be walking? could you not be walking? could he not be walking? could we not be walking? could you not be walking? could they not be walking?
Perfect	V-ing perfect
could I not have walked? could you not have walked? could he not have walked? could we not have walked? could you not have walked? could they not have walked?	could I not have been walking? could you not have been walking? could he not have been walking? could we not have been walking? could you not have been walking? could they not have been walking?