This document outlines three types of conditional sentences in English: zero conditional, first conditional, and second conditional. The zero conditional uses the present simple tense to describe real situations that are always true. The first conditional uses the present simple and will/may/can etc. to describe real possibilities in the present or future. The second conditional uses the past simple and would/could/might etc. to describe hypothetical situations in the present or future. Examples are provided for each type of conditional sentence.