English verb conjugation
COULD UPSHIFT

Regular verb: upshift - upshifted - upshifted

Affirmation

Simple form	V-ing form
I could upshift you could upshift he could upshift we could upshift you could upshift they could upshift	I could be upshifting you could be upshifting he could be upshifting we could be upshifting you could be upshifting they could be upshifting
Perfect	V-ing perfect
I could have upshifted you could have upshifted he could have upshifted we could have upshifted you could have upshifted they could have upshifted	I could have been upshifting you could have been upshifting he could have been upshifting we could have been upshifting you could have been upshifting they could have been upshifting

Negation

Simple form	V-ing form
I could not upshift you could not upshift he could not upshift we could not upshift you could not upshift they could not upshift	I could not be upshifting you could not be upshifting he could not be upshifting we could not be upshifting you could not be upshifting they could not be upshifting
Perfect	V-ing perfect
I could not have upshifted you could not have upshifted he could not have upshifted we could not have upshifted you could not have upshifted they could not have upshifted	I could not have been upshifting you could not have been upshifting he could not have been upshifting we could not have been upshifting you could not have been upshifting they could not have been upshifting

Interrogative form

Simple form	V-ing form
could I upshift? could you upshift? could he upshift? could we upshift? could you upshift? could they upshift?	could I be upshifting? could you be upshifting? could he be upshifting? could we be upshifting? could you be upshifting? could they be upshifting?
Perfect	V-ing perfect
could I have upshifted? could you have upshifted? could he have upshifted? could we have upshifted? could you have upshifted? could they have upshifted?	could I have been upshifting? could you have been upshifting? could he have been upshifting? could we have been upshifting? could you have been upshifting? could they have been upshifting?

Interro-negative form

Simple form	V-ing form
could I not upshift? could you not upshift? could he not upshift? could we not upshift? could you not upshift? could they not upshift?	could I not be upshifting? could you not be upshifting? could he not be upshifting? could we not be upshifting? could you not be upshifting? could they not be upshifting?
Perfect	V-ing perfect
could I not have upshifted? could you not have upshifted? could he not have upshifted? could we not have upshifted? could you not have upshifted? could they not have upshifted?	could I not have been upshifting? could you not have been upshifting? could he not have been upshifting? could we not have been upshifting? could you not have been upshifting? could they not have been upshifting?