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