Inelastic light scattering is used to study the spectra of neutral excitations and magnetoexcitations in single and double quantum wells. New excitation branches of charge, spin, and charge–spin densities are observed. It is shown that various electron and phonon excitation modes interact with one another to form hybrid modes. Exchange and correlation corrections for the combined resonance energies in the integer and fractional Hall effects are estimated. The effect of a spatial inversion asymmetry on the excitation spectra of single-particle and collective excitations is considered.