don't I curb? don't you curb? doesn't he curb? don't we curb? don't you curb? don't they curb?
Present continuous
am I not curbing? aren't you curbing? isn't he curbing? aren't we curbing? aren't you curbing? aren't they curbing?
Preterite
didn't I curb? didn't you curb? didn't he curb? didn't we curb? didn't you curb? didn't they curb?
Preterite continuous
wasn't I curbing? weren't you curbing? wasn't he curbing? weren't we curbing? weren't you curbing? weren't they curbing?
Present perfect
haven't I curbed? haven't you curbed? hasn't he curbed? haven't we curbed? haven't you curbed? haven't they curbed?
Present perfect continuous
haven't I been curbing? haven't you been curbing? hasn't he been curbing? haven't we been curbing? haven't you been curbing? haven't they been curbing?
Pluperfect
hadn't I curbed? hadn't you curbed? hadn't he curbed? hadn't we curbed? hadn't you curbed? hadn't they curbed?
Pluperfect continuous
hadn't I been curbing? hadn't you been curbing? hadn't he been curbing? hadn't we been curbing? hadn't you been curbing? hadn't they been curbing?
Future
won't I curb? won't you curb? won't he curb? won't we curb? won't you curb? won't they curb?
Future continuous
won't I be curbing? won't you be curbing? won't he be curbing? won't we be curbing? won't you be curbing? won't they be curbing?
Future perfect
won't I have curbed? won't you have curbed? won't he have curbed? won't we have curbed? won't you have curbed? won't they have curbed?
Future perfect continuous
won't I have been curbing? won't you have been curbing? won't he have been curbing? won't we have been curbing? won't you have been curbing? won't they have been curbing?
Conditional
Present
wouldn't I curb? wouldn't you curb? wouldn't he curb? wouldn't we curb? wouldn't you curb? wouldn't they curb?
Present continuous
wouldn't I be curbing? wouldn't you be curbing? wouldn't he be curbing? wouldn't we be curbing? wouldn't you be curbing? wouldn't they be curbing?
Past
wouldn't I have curbed? wouldn't you have curbed? wouldn't he have curbed? wouldn't we have curbed? wouldn't you have curbed? wouldn't they have curbed?
Past continuous
wouldn't I have been curbing? wouldn't you have been curbing? wouldn't he have been curbing? wouldn't we have been curbing? wouldn't you have been curbing? wouldn't they have been curbing?