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