The document discusses second conditional sentences, which are used to talk about hypothetical or imaginary situations in the present or future and their consequences. A second conditional sentence is formed with "if" plus the past simple tense followed by "would" and the base form of the verb. Examples are given such as "If I had more money, I'd buy a bigger house" and "If I spoke to him directly, I would convince him." It notes some considerations for using second conditional sentences including using "were" instead of "was" with pronouns like "I" and that the clauses can be reversed.