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 couldn't flush you couldn't flush she 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 she 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 she 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 she 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 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
couldn't I flush? couldn't you flush? couldn't she 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 she 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 she 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 she have been flushing? couldn't we have been flushing? couldn't you have been flushing? couldn't they have been flushing?