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