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