A little bit of etymology helps me remember the difference. "Wary" stems from the same root as "beware" and "aware". Going back further in time, it can also be

A little bit of etymology helps me remember the difference. "Wary" stems from the same root as "beware" and "aware". Going back further in time, it can also be connected to "ward", "warden", and "guard". On the other hand, "weary" stems from "wear", as in "wear and tear", "to wear down", and "this weather has been wearing on me".