  The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-}) ell\nu$
$(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum
rules approach. The heavy quark effective theory prediction of the form factors
as well as $1/m_{b}$ corrections to those form factors are obtained. A
comparison of the results for the ratio of form factors at zero recoil limit
and other values of $q^{2}$ with the predictions of the subleading Isgur-Wise
form factor application for $B\to D^{\ast}\ell\nu$ is presented. The total
decay width and branching ratio for these decays are also evaluated using the
$q^2$ dependencies of these form factors. The results are in good agreement
with the constituent quark meson model and existing experimental data. The
$q=s$ case can also be detected at LHC in the near future.
