I could decide you could decide he could decide we could decide you could decide they could decide
V-ing form
I could be deciding you could be deciding he could be deciding we could be deciding you could be deciding they could be deciding
Perfect
I could have decided you could have decided he could have decided we could have decided you could have decided they could have decided
V-ing perfect
I could have been deciding you could have been deciding he could have been deciding we could have been deciding you could have been deciding they could have been deciding
Negation
Simple form
I could not decide you could not decide he could not decide we could not decide you could not decide they could not decide
V-ing form
I could not be deciding you could not be deciding he could not be deciding we could not be deciding you could not be deciding they could not be deciding
Perfect
I could not have decided you could not have decided he could not have decided we could not have decided you could not have decided they could not have decided
V-ing perfect
I could not have been deciding you could not have been deciding he could not have been deciding we could not have been deciding you could not have been deciding they could not have been deciding
Interrogative form
Simple form
could I decide? could you decide? could he decide? could we decide? could you decide? could they decide?
V-ing form
could I be deciding? could you be deciding? could he be deciding? could we be deciding? could you be deciding? could they be deciding?
Perfect
could I have decided? could you have decided? could he have decided? could we have decided? could you have decided? could they have decided?
V-ing perfect
could I have been deciding? could you have been deciding? could he have been deciding? could we have been deciding? could you have been deciding? could they have been deciding?
Interro-negative form
Simple form
could I not decide? could you not decide? could he not decide? could we not decide? could you not decide? could they not decide?
V-ing form
could I not be deciding? could you not be deciding? could he not be deciding? could we not be deciding? could you not be deciding? could they not be deciding?
Perfect
could I not have decided? could you not have decided? could he not have decided? could we not have decided? could you not have decided? could they not have decided?
V-ing perfect
could I not have been deciding? could you not have been deciding? could he not have been deciding? could we not have been deciding? could you not have been deciding? could they not have been deciding?