  In this paper, we use canonical bundle formulas to prove some generalizations
of an old theorem of Kawamata on the semiampleness of nef and abundant log
canonical divisors. In particular, we show that for klt pairs $(X,B)$ with
$K_X+B$ effective, $L \in Pic (X)$ nef, nefness and abundance of $K_X+B+L$
implies semiampleness. This essentially generalizes Kawamata's theorem to the
setting of generalized abundance.
