Abstract
After an introduction into the experimental investigation of the collective dynamics in liquids by inelastic neutron scattering and the formalism used to describe the dispersion of collective excitations in simple liquids, some of the questions, still open for simple liquids, are discussed in view of the new possibilities, which are provided by a small angle time-of-flight spectrometer with a large well resolving pixel detector, which allows continuous mapping of the dynamical space covered with thermal neutrons in the variable small angle range accessible on the NBS-spectrometer BRISP.