  These lecture notes include the following topics. Chapter 1 deals with QCD
and its global symmetries in the chiral limit, explicit symmetry breaking in
terms of the quark masses, and the concept of Green functions and Ward
identities reflecting the underlying chiral symmetry. In Chapter 2 the idea of
a spontaneous breakdown of a global symmetry is discussed and its consequences
in terms of the Goldstone theorem are demonstrated. Chapter 3 deals with
mesonic chiral perturbation theory and the principles entering the construction
of the chiral Lagrangian are outlined. In Chapter 4 the methods are extended to
include the interaction between Goldstone bosons and baryons in the
single-baryon sector.
