I could advantage you could advantage she could advantage we could advantage you could advantage they could advantage
V-ing form
I could be advantaging you could be advantaging she could be advantaging we could be advantaging you could be advantaging they could be advantaging
Perfect
I could have advantaged you could have advantaged she could have advantaged we could have advantaged you could have advantaged they could have advantaged
V-ing perfect
I could have been advantaging you could have been advantaging she could have been advantaging we could have been advantaging you could have been advantaging they could have been advantaging
Negation
Simple form
I couldn't advantage you couldn't advantage she couldn't advantage we couldn't advantage you couldn't advantage they couldn't advantage
V-ing form
I couldn't be advantaging you couldn't be advantaging she couldn't be advantaging we couldn't be advantaging you couldn't be advantaging they couldn't be advantaging
Perfect
I couldn't have advantaged you couldn't have advantaged she couldn't have advantaged we couldn't have advantaged you couldn't have advantaged they couldn't have advantaged
V-ing perfect
I couldn't have been advantaging you couldn't have been advantaging she couldn't have been advantaging we couldn't have been advantaging you couldn't have been advantaging they couldn't have been advantaging
Interrogative form
Simple form
could I advantage? could you advantage? could she advantage? could we advantage? could you advantage? could they advantage?
V-ing form
could I be advantaging? could you be advantaging? could she be advantaging? could we be advantaging? could you be advantaging? could they be advantaging?
Perfect
could I have advantaged? could you have advantaged? could she have advantaged? could we have advantaged? could you have advantaged? could they have advantaged?
V-ing perfect
could I have been advantaging? could you have been advantaging? could she have been advantaging? could we have been advantaging? could you have been advantaging? could they have been advantaging?
Interro-negative form
Simple form
couldn't I advantage? couldn't you advantage? couldn't she advantage? couldn't we advantage? couldn't you advantage? couldn't they advantage?
V-ing form
couldn't I be advantaging? couldn't you be advantaging? couldn't she be advantaging? couldn't we be advantaging? couldn't you be advantaging? couldn't they be advantaging?
Perfect
couldn't I have advantaged? couldn't you have advantaged? couldn't she have advantaged? couldn't we have advantaged? couldn't you have advantaged? couldn't they have advantaged?
V-ing perfect
couldn't I have been advantaging? couldn't you have been advantaging? couldn't she have been advantaging? couldn't we have been advantaging? couldn't you have been advantaging? couldn't they have been advantaging?