  Some of the recent progress in the physics of pion production induced by
neutrinos on nucleons and nuclei is reviewed from a theoretical perspective.
The importance of Watson's theorem to reconcile ANL and BNL data with the
off-diagonal Goldberger-Treiman relation for the $\Delta(1232)$ is discussed.
The disagreement between MiniBooNE data and theoretical calculations is
presented in the light of the new MINERvA data. The coherent pion production
data on $^{12}$C obtained by MINERvA are also compared to different microscopic
and PCAC models.
