Semileptonic decays provide an excellent environment for testing the Standard Model. Tests of lepton flavour universality using b->clnu decays have shown hints of new physics. In this seminar, an overview of the status of these measurements is given, including the impact of radiative corrections on these types of measurement.
Also CKM matrix elements, and in particular |Vcb|, can be measured using semileptonic B decays. There is a long-standing disagreement between values of |Vcb| measured inclusively or exclusively. The exclusive determination relies on the parametrisation of the form factors of the decay.
Measurements using Bs mesons instead of B mesons can shed a new light on lepton flavour universality, |Vcb| and form factors. They suffer from less backgrounds from excited decays and are easier to compute on a lattice. In this seminar I will present a new measurement of |Vcb| using Bs decays, as well as measurements of Bs->Ds(*)munu form factors, performed by the LHCb experiment. Future prospects for measurements of Vcb, R(Ds) and R(Ds*) are also discussed.