show as a verb is used with an "s" at the end when you are using it with 3rd person singular: he shows, she shows, it shows. With the rest of the subject pronouns: I, You, We, They you use "show": I show, You show, They show, We show. When you talk as an imperative or like giving an order or indication, you say "show": EX: Show me the book, please. As a noun you use shows for plural and show for singular: Example: American Idol is a tv show. I like 3 tv shows: Desperate Housewives, Grey´s Anatomy and 90210 :) I hope that helps.

Your question should be phrased, "When do we use 'show' and 'shows'? Does it work for every word?"