do I not understand? do you not understand? does he not understand? do we not understand? do you not understand? do they not understand?
Present continuous
am I not understanding? are you not understanding? is he not understanding? are we not understanding? are you not understanding? are they not understanding?
Preterite
did I not understand? did you not understand? did he not understand? did we not understand? did you not understand? did they not understand?
Preterite continuous
was I not understanding? were you not understanding? was he not understanding? were we not understanding? were you not understanding? were they not understanding?
Present perfect
have I not understood? have you not understood? has he not understood? have we not understood? have you not understood? have they not understood?
Present perfect continuous
have I not been understanding? have you not been understanding? has he not been understanding? have we not been understanding? have you not been understanding? have they not been understanding?
Pluperfect
had I not understood? had you not understood? had he not understood? had we not understood? had you not understood? had they not understood?
Pluperfect continuous
had I not been understanding? had you not been understanding? had he not been understanding? had we not been understanding? had you not been understanding? had they not been understanding?
Future
will I not understand? will you not understand? will he not understand? will we not understand? will you not understand? will they not understand?
Future continuous
will I not be understanding? will you not be understanding? will he not be understanding? will we not be understanding? will you not be understanding? will they not be understanding?
Future perfect
will I not have understood? will you not have understood? will he not have understood? will we not have understood? will you not have understood? will they not have understood?
Future perfect continuous
will I not have been understanding? will you not have been understanding? will he not have been understanding? will we not have been understanding? will you not have been understanding? will they not have been understanding?
Conditional
Present
would I not understand? would you not understand? would he not understand? would we not understand? would you not understand? would they not understand?
Present continuous
would I not be understanding? would you not be understanding? would he not be understanding? would we not be understanding? would you not be understanding? would they not be understanding?
Past
would I not have understood? would you not have understood? would he not have understood? would we not have understood? would you not have understood? would they not have understood?
Past continuous
would I not have been understanding? would you not have been understanding? would he not have been understanding? would we not have been understanding? would you not have been understanding? would they not have been understanding?