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