English verb conjugation
COULD SULFURIZE

Regular verb: sulfurize - sulfurized - sulfurized

Affirmation

Simple form	V-ing form
I could sulfurize you could sulfurize he could sulfurize we could sulfurize you could sulfurize they could sulfurize	I could be sulfurizing you could be sulfurizing he could be sulfurizing we could be sulfurizing you could be sulfurizing they could be sulfurizing
Perfect	V-ing perfect
I could have sulfurized you could have sulfurized he could have sulfurized we could have sulfurized you could have sulfurized they could have sulfurized	I could have been sulfurizing you could have been sulfurizing he could have been sulfurizing we could have been sulfurizing you could have been sulfurizing they could have been sulfurizing

Negation

Simple form	V-ing form
I could not sulfurize you could not sulfurize he could not sulfurize we could not sulfurize you could not sulfurize they could not sulfurize	I could not be sulfurizing you could not be sulfurizing he could not be sulfurizing we could not be sulfurizing you could not be sulfurizing they could not be sulfurizing
Perfect	V-ing perfect
I could not have sulfurized you could not have sulfurized he could not have sulfurized we could not have sulfurized you could not have sulfurized they could not have sulfurized	I could not have been sulfurizing you could not have been sulfurizing he could not have been sulfurizing we could not have been sulfurizing you could not have been sulfurizing they could not have been sulfurizing

Interrogative form

Simple form	V-ing form
could I sulfurize? could you sulfurize? could he sulfurize? could we sulfurize? could you sulfurize? could they sulfurize?	could I be sulfurizing? could you be sulfurizing? could he be sulfurizing? could we be sulfurizing? could you be sulfurizing? could they be sulfurizing?
Perfect	V-ing perfect
could I have sulfurized? could you have sulfurized? could he have sulfurized? could we have sulfurized? could you have sulfurized? could they have sulfurized?	could I have been sulfurizing? could you have been sulfurizing? could he have been sulfurizing? could we have been sulfurizing? could you have been sulfurizing? could they have been sulfurizing?

Interro-negative form

Simple form	V-ing form
could I not sulfurize? could you not sulfurize? could he not sulfurize? could we not sulfurize? could you not sulfurize? could they not sulfurize?	could I not be sulfurizing? could you not be sulfurizing? could he not be sulfurizing? could we not be sulfurizing? could you not be sulfurizing? could they not be sulfurizing?
Perfect	V-ing perfect
could I not have sulfurized? could you not have sulfurized? could he not have sulfurized? could we not have sulfurized? could you not have sulfurized? could they not have sulfurized?	could I not have been sulfurizing? could you not have been sulfurizing? could he not have been sulfurizing? could we not have been sulfurizing? could you not have been sulfurizing? could they not have been sulfurizing?