I could oxidize you could oxidize he could oxidize we could oxidize you could oxidize they could oxidize
V-ing form
I could be oxidizing you could be oxidizing he could be oxidizing we could be oxidizing you could be oxidizing they could be oxidizing
Perfect
I could have oxidized you could have oxidized he could have oxidized we could have oxidized you could have oxidized they could have oxidized
V-ing perfect
I could have been oxidizing you could have been oxidizing he could have been oxidizing we could have been oxidizing you could have been oxidizing they could have been oxidizing
Negation
Simple form
I could not oxidize you could not oxidize he could not oxidize we could not oxidize you could not oxidize they could not oxidize
V-ing form
I could not be oxidizing you could not be oxidizing he could not be oxidizing we could not be oxidizing you could not be oxidizing they could not be oxidizing
Perfect
I could not have oxidized you could not have oxidized he could not have oxidized we could not have oxidized you could not have oxidized they could not have oxidized
V-ing perfect
I could not have been oxidizing you could not have been oxidizing he could not have been oxidizing we could not have been oxidizing you could not have been oxidizing they could not have been oxidizing
Interrogative form
Simple form
could I oxidize? could you oxidize? could he oxidize? could we oxidize? could you oxidize? could they oxidize?
V-ing form
could I be oxidizing? could you be oxidizing? could he be oxidizing? could we be oxidizing? could you be oxidizing? could they be oxidizing?
Perfect
could I have oxidized? could you have oxidized? could he have oxidized? could we have oxidized? could you have oxidized? could they have oxidized?
V-ing perfect
could I have been oxidizing? could you have been oxidizing? could he have been oxidizing? could we have been oxidizing? could you have been oxidizing? could they have been oxidizing?
Interro-negative form
Simple form
could I not oxidize? could you not oxidize? could he not oxidize? could we not oxidize? could you not oxidize? could they not oxidize?
V-ing form
could I not be oxidizing? could you not be oxidizing? could he not be oxidizing? could we not be oxidizing? could you not be oxidizing? could they not be oxidizing?
Perfect
could I not have oxidized? could you not have oxidized? could he not have oxidized? could we not have oxidized? could you not have oxidized? could they not have oxidized?
V-ing perfect
could I not have been oxidizing? could you not have been oxidizing? could he not have been oxidizing? could we not have been oxidizing? could you not have been oxidizing? could they not have been oxidizing?