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