I could platinize you could platinize he could platinize we could platinize you could platinize they could platinize
V-ing form
I could be platinizing you could be platinizing he could be platinizing we could be platinizing you could be platinizing they could be platinizing
Perfect
I could have platinized you could have platinized he could have platinized we could have platinized you could have platinized they could have platinized
V-ing perfect
I could have been platinizing you could have been platinizing he could have been platinizing we could have been platinizing you could have been platinizing they could have been platinizing
Negation
Simple form
I couldn't platinize you couldn't platinize he couldn't platinize we couldn't platinize you couldn't platinize they couldn't platinize
V-ing form
I couldn't be platinizing you couldn't be platinizing he couldn't be platinizing we couldn't be platinizing you couldn't be platinizing they couldn't be platinizing
Perfect
I couldn't have platinized you couldn't have platinized he couldn't have platinized we couldn't have platinized you couldn't have platinized they couldn't have platinized
V-ing perfect
I couldn't have been platinizing you couldn't have been platinizing he couldn't have been platinizing we couldn't have been platinizing you couldn't have been platinizing they couldn't have been platinizing
Interrogative form
Simple form
could I platinize? could you platinize? could he platinize? could we platinize? could you platinize? could they platinize?
V-ing form
could I be platinizing? could you be platinizing? could he be platinizing? could we be platinizing? could you be platinizing? could they be platinizing?
Perfect
could I have platinized? could you have platinized? could he have platinized? could we have platinized? could you have platinized? could they have platinized?
V-ing perfect
could I have been platinizing? could you have been platinizing? could he have been platinizing? could we have been platinizing? could you have been platinizing? could they have been platinizing?
Interro-negative form
Simple form
couldn't I platinize? couldn't you platinize? couldn't he platinize? couldn't we platinize? couldn't you platinize? couldn't they platinize?
V-ing form
couldn't I be platinizing? couldn't you be platinizing? couldn't he be platinizing? couldn't we be platinizing? couldn't you be platinizing? couldn't they be platinizing?
Perfect
couldn't I have platinized? couldn't you have platinized? couldn't he have platinized? couldn't we have platinized? couldn't you have platinized? couldn't they have platinized?
V-ing perfect
couldn't I have been platinizing? couldn't you have been platinizing? couldn't he have been platinizing? couldn't we have been platinizing? couldn't you have been platinizing? couldn't they have been platinizing?