  We develop a bosonization procedure on the half line. Different boundary
conditions, formulated in terms of the vector and axial fermion currents, are
implemented by using in general the mixed boundary condition on the bosonic
field. The interplay between symmetries and boundary conditions is investigated
in this context, with a particular emphasis on duality. As an application, we
explicitly construct operator solutions of the massless Thirring model on the
half line, respecting different boundary conditions.
