This document introduces the zero conditional, which is used to describe general facts or scientific truths. It states that a zero conditional contains two present simple verbs, with one in the "if clause" and one in the "main clause." Examples are given such as "if people eat too much, they get fat" and "if you touch a fire, you get burned." The rule for a zero conditional is stated as "if" (condition) (result) with "if" followed by a simple present verb and then a simple present verb.