  Particles with negative energies are considered for three different cases:
inside of horizon of Schwarzschild black hole, Milne's coordinates in flat
Minkowski space-time (Milne's universe using nonsynchronous coordinates) and in
cosmological G\"{o}del model of the rotating universe. It is shown that
differently from the G\"{o}del model with nondiagonal term where it occurs that
negative energies are impossible they are present in all other cases considered
in the paper. Particles with zero energy are also possible in first two cases.
