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