I could dilute you could dilute she could dilute we could dilute you could dilute they could dilute
V-ing form
I could be diluting you could be diluting she could be diluting we could be diluting you could be diluting they could be diluting
Perfect
I could have diluted you could have diluted she could have diluted we could have diluted you could have diluted they could have diluted
V-ing perfect
I could have been diluting you could have been diluting she could have been diluting we could have been diluting you could have been diluting they could have been diluting
Negation
Simple form
I could not dilute you could not dilute she could not dilute we could not dilute you could not dilute they could not dilute
V-ing form
I could not be diluting you could not be diluting she could not be diluting we could not be diluting you could not be diluting they could not be diluting
Perfect
I could not have diluted you could not have diluted she could not have diluted we could not have diluted you could not have diluted they could not have diluted
V-ing perfect
I could not have been diluting you could not have been diluting she could not have been diluting we could not have been diluting you could not have been diluting they could not have been diluting
Interrogative form
Simple form
could I dilute? could you dilute? could she dilute? could we dilute? could you dilute? could they dilute?
V-ing form
could I be diluting? could you be diluting? could she be diluting? could we be diluting? could you be diluting? could they be diluting?
Perfect
could I have diluted? could you have diluted? could she have diluted? could we have diluted? could you have diluted? could they have diluted?
V-ing perfect
could I have been diluting? could you have been diluting? could she have been diluting? could we have been diluting? could you have been diluting? could they have been diluting?
Interro-negative form
Simple form
could I not dilute? could you not dilute? could she not dilute? could we not dilute? could you not dilute? could they not dilute?
V-ing form
could I not be diluting? could you not be diluting? could she not be diluting? could we not be diluting? could you not be diluting? could they not be diluting?
Perfect
could I not have diluted? could you not have diluted? could she not have diluted? could we not have diluted? could you not have diluted? could they not have diluted?
V-ing perfect
could I not have been diluting? could you not have been diluting? could she not have been diluting? could we not have been diluting? could you not have been diluting? could they not have been diluting?