  I review the recent theoretical progress on the study of tree-level
semileptonic $b\to c$ decays. After briefly reviewing the latest developments
on the exclusive determinations of $|V_{cb}|$, I discuss the hints on lepton
flavor universality violation in $B\to D^{(\ast)}\ell \bar{\nu}$ decays.
Particular emphasis is given to the implications of these anomalies and to the
possibilities to experimentally test the proposed New Physics explanations.
