I could concertize you could concertize he could concertize we could concertize you could concertize they could concertize
V-ing form
I could be concertizing you could be concertizing he could be concertizing we could be concertizing you could be concertizing they could be concertizing
Perfect
I could have concertized you could have concertized he could have concertized we could have concertized you could have concertized they could have concertized
V-ing perfect
I could have been concertizing you could have been concertizing he could have been concertizing we could have been concertizing you could have been concertizing they could have been concertizing
Negation
Simple form
I could not concertize you could not concertize he could not concertize we could not concertize you could not concertize they could not concertize
V-ing form
I could not be concertizing you could not be concertizing he could not be concertizing we could not be concertizing you could not be concertizing they could not be concertizing
Perfect
I could not have concertized you could not have concertized he could not have concertized we could not have concertized you could not have concertized they could not have concertized
V-ing perfect
I could not have been concertizing you could not have been concertizing he could not have been concertizing we could not have been concertizing you could not have been concertizing they could not have been concertizing
Interrogative form
Simple form
could I concertize? could you concertize? could he concertize? could we concertize? could you concertize? could they concertize?
V-ing form
could I be concertizing? could you be concertizing? could he be concertizing? could we be concertizing? could you be concertizing? could they be concertizing?
Perfect
could I have concertized? could you have concertized? could he have concertized? could we have concertized? could you have concertized? could they have concertized?
V-ing perfect
could I have been concertizing? could you have been concertizing? could he have been concertizing? could we have been concertizing? could you have been concertizing? could they have been concertizing?
Interro-negative form
Simple form
could I not concertize? could you not concertize? could he not concertize? could we not concertize? could you not concertize? could they not concertize?
V-ing form
could I not be concertizing? could you not be concertizing? could he not be concertizing? could we not be concertizing? could you not be concertizing? could they not be concertizing?
Perfect
could I not have concertized? could you not have concertized? could he not have concertized? could we not have concertized? could you not have concertized? could they not have concertized?
V-ing perfect
could I not have been concertizing? could you not have been concertizing? could he not have been concertizing? could we not have been concertizing? could you not have been concertizing? could they not have been concertizing?