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