English verb conjugation
COULD FLUSH

Regular verb: flush - flushed - flushed

Affirmation

Simple form	V-ing form
I could flush you could flush she could flush we could flush you could flush they could flush	I could be flushing you could be flushing she could be flushing we could be flushing you could be flushing they could be flushing
Perfect	V-ing perfect
I could have flushed you could have flushed she could have flushed we could have flushed you could have flushed they could have flushed	I could have been flushing you could have been flushing she could have been flushing we could have been flushing you could have been flushing they could have been flushing

Negation

Simple form	V-ing form
I could not flush you could not flush she could not flush we could not flush you could not flush they could not flush	I could not be flushing you could not be flushing she could not be flushing we could not be flushing you could not be flushing they could not be flushing
Perfect	V-ing perfect
I could not have flushed you could not have flushed she could not have flushed we could not have flushed you could not have flushed they could not have flushed	I could not have been flushing you could not have been flushing she could not have been flushing we could not have been flushing you could not have been flushing they could not have been flushing

Interrogative form

Simple form	V-ing form
could I flush? could you flush? could she flush? could we flush? could you flush? could they flush?	could I be flushing? could you be flushing? could she be flushing? could we be flushing? could you be flushing? could they be flushing?
Perfect	V-ing perfect
could I have flushed? could you have flushed? could she have flushed? could we have flushed? could you have flushed? could they have flushed?	could I have been flushing? could you have been flushing? could she have been flushing? could we have been flushing? could you have been flushing? could they have been flushing?

Interro-negative form

Simple form	V-ing form
could I not flush? could you not flush? could she not flush? could we not flush? could you not flush? could they not flush?	could I not be flushing? could you not be flushing? could she not be flushing? could we not be flushing? could you not be flushing? could they not be flushing?
Perfect	V-ing perfect
could I not have flushed? could you not have flushed? could she not have flushed? could we not have flushed? could you not have flushed? could they not have flushed?	could I not have been flushing? could you not have been flushing? could she not have been flushing? could we not have been flushing? could you not have been flushing? could they not have been flushing?