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