I could revolve you could revolve he could revolve we could revolve you could revolve they could revolve
V-ing form
I could be revolving you could be revolving he could be revolving we could be revolving you could be revolving they could be revolving
Perfect
I could have revolved you could have revolved he could have revolved we could have revolved you could have revolved they could have revolved
V-ing perfect
I could have been revolving you could have been revolving he could have been revolving we could have been revolving you could have been revolving they could have been revolving
Negation
Simple form
I couldn't revolve you couldn't revolve he couldn't revolve we couldn't revolve you couldn't revolve they couldn't revolve
V-ing form
I couldn't be revolving you couldn't be revolving he couldn't be revolving we couldn't be revolving you couldn't be revolving they couldn't be revolving
Perfect
I couldn't have revolved you couldn't have revolved he couldn't have revolved we couldn't have revolved you couldn't have revolved they couldn't have revolved
V-ing perfect
I couldn't have been revolving you couldn't have been revolving he couldn't have been revolving we couldn't have been revolving you couldn't have been revolving they couldn't have been revolving
Interrogative form
Simple form
could I revolve? could you revolve? could he revolve? could we revolve? could you revolve? could they revolve?
V-ing form
could I be revolving? could you be revolving? could he be revolving? could we be revolving? could you be revolving? could they be revolving?
Perfect
could I have revolved? could you have revolved? could he have revolved? could we have revolved? could you have revolved? could they have revolved?
V-ing perfect
could I have been revolving? could you have been revolving? could he have been revolving? could we have been revolving? could you have been revolving? could they have been revolving?
Interro-negative form
Simple form
couldn't I revolve? couldn't you revolve? couldn't he revolve? couldn't we revolve? couldn't you revolve? couldn't they revolve?
V-ing form
couldn't I be revolving? couldn't you be revolving? couldn't he be revolving? couldn't we be revolving? couldn't you be revolving? couldn't they be revolving?
Perfect
couldn't I have revolved? couldn't you have revolved? couldn't he have revolved? couldn't we have revolved? couldn't you have revolved? couldn't they have revolved?
V-ing perfect
couldn't I have been revolving? couldn't you have been revolving? couldn't he have been revolving? couldn't we have been revolving? couldn't you have been revolving? couldn't they have been revolving?