English verb conjugation
COULD PIFFLE

Regular verb: piffle - piffled - piffled

Affirmation

Simple form	V-ing form
I could piffle you could piffle he could piffle we could piffle you could piffle they could piffle	I could be piffling you could be piffling he could be piffling we could be piffling you could be piffling they could be piffling
Perfect	V-ing perfect
I could have piffled you could have piffled he could have piffled we could have piffled you could have piffled they could have piffled	I could have been piffling you could have been piffling he could have been piffling we could have been piffling you could have been piffling they could have been piffling

Negation

Simple form	V-ing form
I could not piffle you could not piffle he could not piffle we could not piffle you could not piffle they could not piffle	I could not be piffling you could not be piffling he could not be piffling we could not be piffling you could not be piffling they could not be piffling
Perfect	V-ing perfect
I could not have piffled you could not have piffled he could not have piffled we could not have piffled you could not have piffled they could not have piffled	I could not have been piffling you could not have been piffling he could not have been piffling we could not have been piffling you could not have been piffling they could not have been piffling

Interrogative form

Simple form	V-ing form
could I piffle? could you piffle? could he piffle? could we piffle? could you piffle? could they piffle?	could I be piffling? could you be piffling? could he be piffling? could we be piffling? could you be piffling? could they be piffling?
Perfect	V-ing perfect
could I have piffled? could you have piffled? could he have piffled? could we have piffled? could you have piffled? could they have piffled?	could I have been piffling? could you have been piffling? could he have been piffling? could we have been piffling? could you have been piffling? could they have been piffling?

Interro-negative form

Simple form	V-ing form
could I not piffle? could you not piffle? could he not piffle? could we not piffle? could you not piffle? could they not piffle?	could I not be piffling? could you not be piffling? could he not be piffling? could we not be piffling? could you not be piffling? could they not be piffling?
Perfect	V-ing perfect
could I not have piffled? could you not have piffled? could he not have piffled? could we not have piffled? could you not have piffled? could they not have piffled?	could I not have been piffling? could you not have been piffling? could he not have been piffling? could we not have been piffling? could you not have been piffling? could they not have been piffling?