  We study the parametric amplification of super-Hubble-scale scalar metric
fluctuations at the end of inflation in some specific two-field models of
inflation, a class of which is motivated by hybrid inflation. We demonstrate
that there can indeed be a large growth of fluctuations due to parametric
resonance and that this effect is not taken into account by the conventional
theory of isocurvature perturbations. Scalar field interactions play a crucial
role in this analysis. We discuss the conditions under which there can be
nontrivial parametric resonance effects on large scales.
