The document provides examples of conditional sentences using "if" to express possible situations and their consequences. It discusses the structure of sentences using "if" followed by the present simple tense and "will/won't" plus an infinitive verb. Examples are given of conditional sentences expressing superstitions and their potential consequences. The document notes that modal verbs other than "will/won't" can also be used after "if" such as "can", "might", "may", "must", and "should".