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