We present a sequent calculus for the modal logic S4, and building on
some relevant features of this system (the absence of contraction rule
s and the confinement of weakenings into axioms and modal rules) we sh
ow how S4 can easily be translated into full propositional linear logi
c, extending the Grishin-Ono translation of classical logic into linea
r logic. The translation introduces linear modalities (exponentials) o
nly in correspondence with S4 modalities. We discuss the complexity of
the decision problem for several classes of linear formulas naturally
arising from the proposed translations.