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