  Like the two-photon and two-gluon decays of the $P$-wave $\chi_{c0,2}$ and
$\chi_{b0,2}$ charmonium state for which the Born term produces a very simple
decgays amplitude in terms of an effective Lagrangian with two-quark local
operator, the Born term for the processes $c\bar{d} \to (\pi,K) \ell \nu $ and
$b \bar{d}\to (\pi, K) \ell\nu $, could also produce the $D$ and $B$ meson
semileptonic decays with the light meson $\pi, K$ in the final state. In this
approach to heavy-light meson form factors with the $\pi$, K meson treated as
Goldstone boson, a simple expression is found for the decays form factors,
given as~: $ f_{+}(0)/(1 -q^{2}/(m_{H}^{2}+ m_{\pi}^{2}))$, with $H=D,B$ for
$D,B \to \pi$ form factors, and $f_{+}(0)/(1 -q^{2}/(m_{H}^{2}+ m_{K}^{2}))$
for $B,D\to K$ form factor. The purpose of this paper is to show that this
expression for the form factors could describe rather well the $q^{2}$-
behaviour observed in the BaBar, Belle and BESIII measurements and lattice
simulation. In particular, the $D\to K$ form factors are in good agreement with
the measured values in the whole range of $q^{2}$ showing evidence for $SU(3)$
breaking with the presence of $m_{K}^{2}$ term in the quark propagator, but
some corrections to the Born term are needed at large $q^{2}$ for $D,B \to \pi$
form factors.
