# Why does light not polarise off metallic surface?

I am aware that light partially polarizes upon reflection off a non-metallic surface, however, why is it that this only occurs for non-metallic surfaces?

Because of to presence of free electrons in a metal the incident electric field does not penetrate very far into a metal $(\approx 10^{-8} \,\rm m)$ whereas the electric field does penetrate into a dielectric.