  We study some properties of the solutions of (E) $\;-\Gd_p u+|\nabla u|^q=0$
in a domain $\Gw \sbs \BBR^N$, mostly when $p\geq q>p-1$. We give a universal
priori estimate of the gradient of the solutions with respect to the distance
to the boundary. We give a full classification of the isolated singularities of
the positive solutions of (E), a partial classification of isolated
singularities of the negative solutions. We prove a general removability result
in expressed in terms of some Bessel capacity of the removable set. We extend
our estimates to equations on complete non compact manifolds satisfying a lower
bound estimate on the Ricci curvature, and derive some Liouville type theorems.
