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