English verb conjugation
COULD SUMMARIZE

Regular verb: summarize - summarized - summarized

Affirmation

Simple form	V-ing form
I could summarize you could summarize she could summarize we could summarize you could summarize they could summarize	I could be summarizing you could be summarizing she could be summarizing we could be summarizing you could be summarizing they could be summarizing
Perfect	V-ing perfect
I could have summarized you could have summarized she could have summarized we could have summarized you could have summarized they could have summarized	I could have been summarizing you could have been summarizing she could have been summarizing we could have been summarizing you could have been summarizing they could have been summarizing

Negation

Simple form	V-ing form
I couldn't summarize you couldn't summarize she couldn't summarize we couldn't summarize you couldn't summarize they couldn't summarize	I couldn't be summarizing you couldn't be summarizing she couldn't be summarizing we couldn't be summarizing you couldn't be summarizing they couldn't be summarizing
Perfect	V-ing perfect
I couldn't have summarized you couldn't have summarized she couldn't have summarized we couldn't have summarized you couldn't have summarized they couldn't have summarized	I couldn't have been summarizing you couldn't have been summarizing she couldn't have been summarizing we couldn't have been summarizing you couldn't have been summarizing they couldn't have been summarizing

Interrogative form

Simple form	V-ing form
could I summarize? could you summarize? could she summarize? could we summarize? could you summarize? could they summarize?	could I be summarizing? could you be summarizing? could she be summarizing? could we be summarizing? could you be summarizing? could they be summarizing?
Perfect	V-ing perfect
could I have summarized? could you have summarized? could she have summarized? could we have summarized? could you have summarized? could they have summarized?	could I have been summarizing? could you have been summarizing? could she have been summarizing? could we have been summarizing? could you have been summarizing? could they have been summarizing?

Interro-negative form

Simple form	V-ing form
couldn't I summarize? couldn't you summarize? couldn't she summarize? couldn't we summarize? couldn't you summarize? couldn't they summarize?	couldn't I be summarizing? couldn't you be summarizing? couldn't she be summarizing? couldn't we be summarizing? couldn't you be summarizing? couldn't they be summarizing?
Perfect	V-ing perfect
couldn't I have summarized? couldn't you have summarized? couldn't she have summarized? couldn't we have summarized? couldn't you have summarized? couldn't they have summarized?	couldn't I have been summarizing? couldn't you have been summarizing? couldn't she have been summarizing? couldn't we have been summarizing? couldn't you have been summarizing? couldn't they have been summarizing?