  A summary of WG II of the CKM 2018 conference on semileptonic and leptonic
$b$-hadron decays is presented. This includes discussions on the CKM matrix
element magitudes $|V_{ub}|$ and $|V_{cb}|$, lepton universality tests such as
$R(D^{*})$ and leptonic decays. As is usual for semileptonic and leptonic
decays, much discussion is devoted towards the interplay between theoretical
QCD calculations and the experimental measurements.
