1) The document discusses the use of relative clauses in English, which are commonly used for postmodification. It provides 4 example sentences using relative pronouns like "who" and "that" to modify nouns.
2) The examples are analyzed in detail, explaining the antecedents of the relative pronouns and how they link together parts of each sentence.
3) Mastering the use of relative pronouns and being able to identify their antecedents is important for accurately comprehending relationships within sentences.