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