  The quasielastic production cross sections and polarizations of the hyperons
induced by ${\bar\nu}_\mu$ on the free nucleon as well as from $^{40}$Ar in the
sub-GeV energy region has been reviewed [1-5]. The effects of the second class
currents in the axial vector sector with and without T-invariance as well as
the effect of SU(3) symmetry breaking are also studied. We find that the cross
sections and the various polarization components can effectively be used to
determine the axial vector transition form factors in the strangeness sector
and to test the validity of various symmetries of the weak hadronic currents
like G-invariance, T-invariance and SU(3) symmetry.
  These hyperons decay dominantly into pions giving an additional contribution
to the weak pion production induced by the antineutrinos. In the case of
nuclear targets like $^{40}$Ar, this contribution is shown to be significant
when compared with the pion production by the $\Delta$ excitations in the
energy range of $E_{\bar{\nu}_{\mu}} \le 0.7$ GeV [1]. This study could be
useful for the DUNE experiment where argon will be used as the target material
and the electronic imaging of particles is possible and the particle tracks can
be identified.
