I could benefit you could benefit he could benefit we could benefit you could benefit they could benefit
V-ing form
I could be benefiting you could be benefiting he could be benefiting we could be benefiting you could be benefiting they could be benefiting
Perfect
I could have benefited you could have benefited he 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 he 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 he 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 he 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 he 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 he 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 he benefit? could we benefit? could you benefit? could they benefit?
V-ing form
could I be benefiting? could you be benefiting? could he be benefiting? could we be benefiting? could you be benefiting? could they be benefiting?
Perfect
could I have benefited? could you have benefited? could he 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 he 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 he 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 he 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 he 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 he have been benefiting? couldn't we have been benefiting? couldn't you have been benefiting? couldn't they have been benefiting?