I could devolve you could devolve he could devolve we could devolve you could devolve they could devolve
V-ing form
I could be devolving you could be devolving he could be devolving we could be devolving you could be devolving they could be devolving
Perfect
I could have devolved you could have devolved he could have devolved we could have devolved you could have devolved they could have devolved
V-ing perfect
I could have been devolving you could have been devolving he could have been devolving we could have been devolving you could have been devolving they could have been devolving
Negation
Simple form
I could not devolve you could not devolve he could not devolve we could not devolve you could not devolve they could not devolve
V-ing form
I could not be devolving you could not be devolving he could not be devolving we could not be devolving you could not be devolving they could not be devolving
Perfect
I could not have devolved you could not have devolved he could not have devolved we could not have devolved you could not have devolved they could not have devolved
V-ing perfect
I could not have been devolving you could not have been devolving he could not have been devolving we could not have been devolving you could not have been devolving they could not have been devolving
Interrogative form
Simple form
could I devolve? could you devolve? could he devolve? could we devolve? could you devolve? could they devolve?
V-ing form
could I be devolving? could you be devolving? could he be devolving? could we be devolving? could you be devolving? could they be devolving?
Perfect
could I have devolved? could you have devolved? could he have devolved? could we have devolved? could you have devolved? could they have devolved?
V-ing perfect
could I have been devolving? could you have been devolving? could he have been devolving? could we have been devolving? could you have been devolving? could they have been devolving?
Interro-negative form
Simple form
could I not devolve? could you not devolve? could he not devolve? could we not devolve? could you not devolve? could they not devolve?
V-ing form
could I not be devolving? could you not be devolving? could he not be devolving? could we not be devolving? could you not be devolving? could they not be devolving?
Perfect
could I not have devolved? could you not have devolved? could he not have devolved? could we not have devolved? could you not have devolved? could they not have devolved?
V-ing perfect
could I not have been devolving? could you not have been devolving? could he not have been devolving? could we not have been devolving? could you not have been devolving? could they not have been devolving?