Let $X$ be a minimal, smooth and projective algebraic surface of general type over the complex numbers. Then the ampleness of $K_X$ has a very geometric interpretation: $K_X$ is ample if and only if $X$ does not contain $(-2)$-curves.
Let $Y$ be a minimal, normal and projective algebraic surface of general type over the complex numbers. Is there a similar characterization in this case? If $Y$ had a $(-2)$-curve, then $K_Y$ would not be ample by the Nakai-Moishezon criterion. Is the absence of $(-2)$-curves enough to claim that $K_Y$ is ample? I am wondering whether there could be $(-2)$-curves "hidden" in the singularities preventing $K_Y$ to be ample. More precisely, there could be a curve passing through a singularity $P$ of $Y$ that becomes a $(-2)$-curve after resolving $P$ causing $K_Y$ not to be ample.
Any help or reference would be appreciated.