  We study the mechanism of production of the light scalar mesons in the
$D_s^+\to\pi^+\pi^- e^+\nu$ decays: $D_s^+\to s\bar s e^+\nu\to
[\sigma(600)+f_0(980)] e^+\nu\to\pi^+\pi^- e^+\nu$, and compare it with the
mechanism of production of the light pseudoscalar mesons in the $D_s^+\to
(\eta/\eta') e^+\nu$ decays: $D_s^+\to s\bar s e^+\nu\to (\eta/\eta')e^+\nu$.
We show that the $s\bar s\to\sigma(600)$ transition is negligibly small in
comparison with the $s\bar s\to f_0(980)$ one. As for the the $f_0(980)$ meson,
the intensity of the $s\bar s\to f_0(980)$ transition makes near thirty percent
from the intensity of the $s\bar s\to\eta_s$ ($\eta_s=s\bar s$) transition. So,
the $D_s^+\to\pi^+\pi^- e^+\nu$ decay supports the previous conclusions about a
dominant role of the four-quark components in the $\sigma(600)$ and $f_0(980)$
mesons.
