English verb conjugation
COULD FLUSH

Regular verb: flush - flushed - flushed

Affirmation

Simple form	V-ing form
I could flush you could flush he could flush we could flush you could flush they could flush	I could be flushing you could be flushing he 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 he 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 he 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 couldn't flush you couldn't flush he couldn't flush we couldn't flush you couldn't flush they couldn't flush	I couldn't be flushing you couldn't be flushing he couldn't be flushing we couldn't be flushing you couldn't be flushing they couldn't be flushing
Perfect	V-ing perfect
I couldn't have flushed you couldn't have flushed he couldn't have flushed we couldn't have flushed you couldn't have flushed they couldn't have flushed	I couldn't have been flushing you couldn't have been flushing he couldn't have been flushing we couldn't have been flushing you couldn't have been flushing they couldn't have been flushing

Interrogative form

Simple form	V-ing form
could I flush? could you flush? could he flush? could we flush? could you flush? could they flush?	could I be flushing? could you be flushing? could he 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 he 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 he 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
couldn't I flush? couldn't you flush? couldn't he flush? couldn't we flush? couldn't you flush? couldn't they flush?	couldn't I be flushing? couldn't you be flushing? couldn't he be flushing? couldn't we be flushing? couldn't you be flushing? couldn't they be flushing?
Perfect	V-ing perfect
couldn't I have flushed? couldn't you have flushed? couldn't he have flushed? couldn't we have flushed? couldn't you have flushed? couldn't they have flushed?	couldn't I have been flushing? couldn't you have been flushing? couldn't he have been flushing? couldn't we have been flushing? couldn't you have been flushing? couldn't they have been flushing?