I could backfire you could backfire he could backfire we could backfire you could backfire they could backfire
V-ing form
I could be backfiring you could be backfiring he could be backfiring we could be backfiring you could be backfiring they could be backfiring
Perfect
I could have backfired you could have backfired he could have backfired we could have backfired you could have backfired they could have backfired
V-ing perfect
I could have been backfiring you could have been backfiring he could have been backfiring we could have been backfiring you could have been backfiring they could have been backfiring
Negation
Simple form
I could not backfire you could not backfire he could not backfire we could not backfire you could not backfire they could not backfire
V-ing form
I could not be backfiring you could not be backfiring he could not be backfiring we could not be backfiring you could not be backfiring they could not be backfiring
Perfect
I could not have backfired you could not have backfired he could not have backfired we could not have backfired you could not have backfired they could not have backfired
V-ing perfect
I could not have been backfiring you could not have been backfiring he could not have been backfiring we could not have been backfiring you could not have been backfiring they could not have been backfiring
Interrogative form
Simple form
could I backfire? could you backfire? could he backfire? could we backfire? could you backfire? could they backfire?
V-ing form
could I be backfiring? could you be backfiring? could he be backfiring? could we be backfiring? could you be backfiring? could they be backfiring?
Perfect
could I have backfired? could you have backfired? could he have backfired? could we have backfired? could you have backfired? could they have backfired?
V-ing perfect
could I have been backfiring? could you have been backfiring? could he have been backfiring? could we have been backfiring? could you have been backfiring? could they have been backfiring?
Interro-negative form
Simple form
could I not backfire? could you not backfire? could he not backfire? could we not backfire? could you not backfire? could they not backfire?
V-ing form
could I not be backfiring? could you not be backfiring? could he not be backfiring? could we not be backfiring? could you not be backfiring? could they not be backfiring?
Perfect
could I not have backfired? could you not have backfired? could he not have backfired? could we not have backfired? could you not have backfired? could they not have backfired?
V-ing perfect
could I not have been backfiring? could you not have been backfiring? could he not have been backfiring? could we not have been backfiring? could you not have been backfiring? could they not have been backfiring?