I could jar you could jar he could jar we could jar you could jar they could jar
V-ing form
I could be jarring you could be jarring he could be jarring we could be jarring you could be jarring they could be jarring
Perfect
I could have jarred you could have jarred he could have jarred we could have jarred you could have jarred they could have jarred
V-ing perfect
I could have been jarring you could have been jarring he could have been jarring we could have been jarring you could have been jarring they could have been jarring
Negation
Simple form
I could not jar you could not jar he could not jar we could not jar you could not jar they could not jar
V-ing form
I could not be jarring you could not be jarring he could not be jarring we could not be jarring you could not be jarring they could not be jarring
Perfect
I could not have jarred you could not have jarred he could not have jarred we could not have jarred you could not have jarred they could not have jarred
V-ing perfect
I could not have been jarring you could not have been jarring he could not have been jarring we could not have been jarring you could not have been jarring they could not have been jarring
Interrogative form
Simple form
could I jar? could you jar? could he jar? could we jar? could you jar? could they jar?
V-ing form
could I be jarring? could you be jarring? could he be jarring? could we be jarring? could you be jarring? could they be jarring?
Perfect
could I have jarred? could you have jarred? could he have jarred? could we have jarred? could you have jarred? could they have jarred?
V-ing perfect
could I have been jarring? could you have been jarring? could he have been jarring? could we have been jarring? could you have been jarring? could they have been jarring?
Interro-negative form
Simple form
could I not jar? could you not jar? could he not jar? could we not jar? could you not jar? could they not jar?
V-ing form
could I not be jarring? could you not be jarring? could he not be jarring? could we not be jarring? could you not be jarring? could they not be jarring?
Perfect
could I not have jarred? could you not have jarred? could he not have jarred? could we not have jarred? could you not have jarred? could they not have jarred?
V-ing perfect
could I not have been jarring? could you not have been jarring? could he not have been jarring? could we not have been jarring? could you not have been jarring? could they not have been jarring?