Quasiparticle concept -- Pomeranchuk stability conditions -- Collective excitations and zero sound -- Scattering theory -- Fermi liquid regime of the Kondo problem -- Response of an ideal Fermi gas -- Collective excitations -- Effect of disorder on electron interactions -- Bridging phenomenological and microscopic aspects -- Effect of ampere forces in Fermi liquids -- Overscreened Kondo model and Nozières-Blandin theory -- Electron lifetime in a mesoscopic conductor -- Marginal Fermi liquids