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