I could parenthesize you could parenthesize he could parenthesize we could parenthesize you could parenthesize they could parenthesize
V-ing form
I could be parenthesizing you could be parenthesizing he could be parenthesizing we could be parenthesizing you could be parenthesizing they could be parenthesizing
Perfect
I could have parenthesized you could have parenthesized he could have parenthesized we could have parenthesized you could have parenthesized they could have parenthesized
V-ing perfect
I could have been parenthesizing you could have been parenthesizing he could have been parenthesizing we could have been parenthesizing you could have been parenthesizing they could have been parenthesizing
Negation
Simple form
I could not parenthesize you could not parenthesize he could not parenthesize we could not parenthesize you could not parenthesize they could not parenthesize
V-ing form
I could not be parenthesizing you could not be parenthesizing he could not be parenthesizing we could not be parenthesizing you could not be parenthesizing they could not be parenthesizing
Perfect
I could not have parenthesized you could not have parenthesized he could not have parenthesized we could not have parenthesized you could not have parenthesized they could not have parenthesized
V-ing perfect
I could not have been parenthesizing you could not have been parenthesizing he could not have been parenthesizing we could not have been parenthesizing you could not have been parenthesizing they could not have been parenthesizing
Interrogative form
Simple form
could I parenthesize? could you parenthesize? could he parenthesize? could we parenthesize? could you parenthesize? could they parenthesize?
V-ing form
could I be parenthesizing? could you be parenthesizing? could he be parenthesizing? could we be parenthesizing? could you be parenthesizing? could they be parenthesizing?
Perfect
could I have parenthesized? could you have parenthesized? could he have parenthesized? could we have parenthesized? could you have parenthesized? could they have parenthesized?
V-ing perfect
could I have been parenthesizing? could you have been parenthesizing? could he have been parenthesizing? could we have been parenthesizing? could you have been parenthesizing? could they have been parenthesizing?
Interro-negative form
Simple form
could I not parenthesize? could you not parenthesize? could he not parenthesize? could we not parenthesize? could you not parenthesize? could they not parenthesize?
V-ing form
could I not be parenthesizing? could you not be parenthesizing? could he not be parenthesizing? could we not be parenthesizing? could you not be parenthesizing? could they not be parenthesizing?
Perfect
could I not have parenthesized? could you not have parenthesized? could he not have parenthesized? could we not have parenthesized? could you not have parenthesized? could they not have parenthesized?
V-ing perfect
could I not have been parenthesizing? could you not have been parenthesizing? could he not have been parenthesizing? could we not have been parenthesizing? could you not have been parenthesizing? could they not have been parenthesizing?