The document discusses the second conditional and its structure. It notes that the second conditional refers to unlikely future events. It provides examples of sentences using the second conditional form, showing that the "if" clause can come at the beginning or end of the sentence. It also shows that "would" can be replaced with "'d" and "could" can be used instead of "would". Finally, it indicates that in the conditional statement, the verb after "if" is in the past tense.