1. Anybody does not sleep well during the night.
2. Not anybody sleeps well during the night.
3. Nobody sleeps during the night.
(Is #1 grammatical? Are they all the same in meaning?)
4. None were present at the meeting.
5. No one were present at the meeting.
6. None was present at the meeting.
7. No one was present at the meeting.
(Which ones are grammatical? Do we have to use a singular verb or a plural verb? Does the four sentences have the same meaning?))
http://grammar.ccc.commnet.edu/grammar/pronouns.htm See #1 here.
and
http://grammar.ccc.commnet.edu/grammar/pronouns1.htm#indefinite Read the first line here and make note of the specific pronouns named.
#3, #4, #6, and #7 are correct.