I could summarize you could summarize he could summarize we could summarize you could summarize they could summarize
V-ing form
I could be summarizing you could be summarizing he could be summarizing we could be summarizing you could be summarizing they could be summarizing
Perfect
I could have summarized you could have summarized he could have summarized we could have summarized you could have summarized they could have summarized
V-ing perfect
I could have been summarizing you could have been summarizing he could have been summarizing we could have been summarizing you could have been summarizing they could have been summarizing
Negation
Simple form
I could not summarize you could not summarize he could not summarize we could not summarize you could not summarize they could not summarize
V-ing form
I could not be summarizing you could not be summarizing he could not be summarizing we could not be summarizing you could not be summarizing they could not be summarizing
Perfect
I could not have summarized you could not have summarized he could not have summarized we could not have summarized you could not have summarized they could not have summarized
V-ing perfect
I could not have been summarizing you could not have been summarizing he could not have been summarizing we could not have been summarizing you could not have been summarizing they could not have been summarizing
Interrogative form
Simple form
could I summarize? could you summarize? could he summarize? could we summarize? could you summarize? could they summarize?
V-ing form
could I be summarizing? could you be summarizing? could he be summarizing? could we be summarizing? could you be summarizing? could they be summarizing?
Perfect
could I have summarized? could you have summarized? could he have summarized? could we have summarized? could you have summarized? could they have summarized?
V-ing perfect
could I have been summarizing? could you have been summarizing? could he have been summarizing? could we have been summarizing? could you have been summarizing? could they have been summarizing?
Interro-negative form
Simple form
could I not summarize? could you not summarize? could he not summarize? could we not summarize? could you not summarize? could they not summarize?
V-ing form
could I not be summarizing? could you not be summarizing? could he not be summarizing? could we not be summarizing? could you not be summarizing? could they not be summarizing?
Perfect
could I not have summarized? could you not have summarized? could he not have summarized? could we not have summarized? could you not have summarized? could they not have summarized?
V-ing perfect
could I not have been summarizing? could you not have been summarizing? could he not have been summarizing? could we not have been summarizing? could you not have been summarizing? could they not have been summarizing?