English verb conjugation
COULD SULFURIZE

Regular verb: sulfurize - sulfurized - sulfurized

Affirmation

Simple form	V-ing form
I could sulfurize you could sulfurize she could sulfurize we could sulfurize you could sulfurize they could sulfurize	I could be sulfurizing you could be sulfurizing she 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 she 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 she 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 couldn't sulfurize you couldn't sulfurize she couldn't sulfurize we couldn't sulfurize you couldn't sulfurize they couldn't sulfurize	I couldn't be sulfurizing you couldn't be sulfurizing she couldn't be sulfurizing we couldn't be sulfurizing you couldn't be sulfurizing they couldn't be sulfurizing
Perfect	V-ing perfect
I couldn't have sulfurized you couldn't have sulfurized she couldn't have sulfurized we couldn't have sulfurized you couldn't have sulfurized they couldn't have sulfurized	I couldn't have been sulfurizing you couldn't have been sulfurizing she couldn't have been sulfurizing we couldn't have been sulfurizing you couldn't have been sulfurizing they couldn't have been sulfurizing

Interrogative form

Simple form	V-ing form
could I sulfurize? could you sulfurize? could she sulfurize? could we sulfurize? could you sulfurize? could they sulfurize?	could I be sulfurizing? could you be sulfurizing? could she 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 she 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 she 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
couldn't I sulfurize? couldn't you sulfurize? couldn't she sulfurize? couldn't we sulfurize? couldn't you sulfurize? couldn't they sulfurize?	couldn't I be sulfurizing? couldn't you be sulfurizing? couldn't she be sulfurizing? couldn't we be sulfurizing? couldn't you be sulfurizing? couldn't they be sulfurizing?
Perfect	V-ing perfect
couldn't I have sulfurized? couldn't you have sulfurized? couldn't she have sulfurized? couldn't we have sulfurized? couldn't you have sulfurized? couldn't they have sulfurized?	couldn't I have been sulfurizing? couldn't you have been sulfurizing? couldn't she have been sulfurizing? couldn't we have been sulfurizing? couldn't you have been sulfurizing? couldn't they have been sulfurizing?