  Several lattice collaborations performing simulations with 2+1 light
dynamical quarks have experienced difficulties in fitting their data with
standard Nf=3 chiral expansions at next-to-leading order, yielding low values
of the quark condensate and/or the decay constant in the Nf=3 chiral limit. A
reordering of these expansions seems required to analyse these data in a
consistent way. We discuss such a reordering, known as Resummed Chiral
Perturbation Theory, in the case of pseudoscalar masses and decay constants,
pion and kaon electromagnetic form factors and Kl3} form factors. We show that
it provides a good fit of the recent results of two lattice collaborations
(PACS-CS and RBC/UKQCD). We describe the emerging picture for the pattern of
chiral symmetry breaking, marked by a strong dependence of the observables on
the strange quark mass and thus a significant difference between chiral
symmetry breaking in the Nf=2 and Nf=3 chiral limits. We discuss the
consequences for the ratio of decay constants F_K/F_pi and the Kl3 form factor
at vanishing momentum transfer.
