[en] The two isotopes of helium offer unique opportunities to test fundamental theories of quantum fluids. In the case of liquid ⁴He, a Bose liquid, the elementary excitations have been studied extensively over the last two decades by neutron inelastic scattering. Similar studies of liquid ³He, the Fermi liquid counterpart of liquid ⁴He, have become possible only recently. From the results obtained so far for normal liquid ³He the existence of zero sound as a well defined density excitation at finite wave-vectors (q approx. = q/sub F/) and finite temperatures (T approx. = T/sub F/) has been verified and the spin fluctuation spectrum has been measured. By comparing the neutron scattering results for the density fluctuation spectrum to RPA calculations with generalized polarization potentials important information has been obtained about the effective spin-symmetric interaction between ³He atoms. The spin fluctuation spectrum is in agreement with the paramagnon model if a value close to unity is assumed for the contact dimensionless paramagnon parameter anti I. This implies that the nuclear spin system in normal liquid ³He is close to ferromagnetic