  We review how a certain effective chiral Lagrangian approach to pi pi
scattering, pi K scattering and eta-prime decay to eta pi pi provides evidence
for the existence of light scalars sigma(550) and kappa(900) as well as
describing the f0(980) and the a0(980). An attempt to fit these into a nonet
suggests that their structure is closer to a dual quark-dual antiquark than to
a quark-antiquark. A possible mechanism to explain the next higher mass scalar
nonet is also proposed.
