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