  We use a continuum quark+diquark approach to the nucleon bound-state problem
in relativistic quantum field theory to deliver parameter-free predictions for
the nucleon axial and induced pseudoscalar form factors, $G_A$ and $G_P$, and
unify them with the pseudoscalar form factor $G_5$ or, equivalently, the
pion-nucleon form factor $G_{\pi NN}$. We explain how partial conservation of
the axial-vector current and the associated Goldberger-Treiman relation are
satisfied once all necessary couplings of the external current to the building
blocks of the nucleon are constructed consistently; in particular, we fully
resolve the seagull couplings to the diquark-quark vertices associated with the
axial-vector and pseudoscalar currents. Among the results we describe, the
following are worth highlighting. A dipole form factor defined by an axial
charge $g_A=G_A(0)=1.25(3)$ and a mass-scale $M_A = 1.23(3) m_N$, where $m_N$
is the nucleon mass, can accurately describe the pointwise behaviour of $G_A$.
Concerning $G_P$, we obtain the pseudoscalar charge $g_p^\ast = 8.80(23)$, and
find that the pion pole dominance approach delivers a reliable estimate of the
directly computed result. Our computed value of the pion-nucleon coupling
constant, $g_{\pi NN}/m_N =14.02(33)/{\rm GeV}$ is consistent with recent
precision determinations.
