  We study the symmetry reduction of nonlinear partial differential equations
with two independent variables. We propose new ans\"atze reducing nonlinear
evolution equations to system of ordinary differential equations. The ans\"atze
are constructed by using operators of non-point classical and conditional
symmetry. Then we find solution to nonlinear heat equation which can not be
obtained in the framework of the classical Lie approach. By using operators of
Lie--B\"acklund symmetries we construct the solutions of nonlinear hyperbolic
equations depending on arbitrary smooth function of one variable too. We show
that the method can be applied to nonevolutionary partial differential
equations.
