In linguistics and grammar, a pronoun is a word that substitutes for a noun or noun phrase. It is a particular case of a pro-form. Pronouns have traditionally been regarded as one of the parts of speech, but some modern theorists would not limit them to a single class because of the variety of functions they perform, including that of the personal pronouns, relative pronouns, interrogative pronouns, demonstrative pronouns, possessive pronouns, and indefinite pronouns. The use of pronouns often involves anaphora, where the meaning of the pronoun is dependent on another referential element. This applies particularly to the (third-person) personal pronouns. The referent of the pronoun is often the same as that of a preceding (or sometimes following) noun phrase, called the antecedent of the pronoun. For example, in the sentence That poor man looks as if he needs a new coat, the antecedent of the pronoun he is the noun phrase that poor man. (Pronouns used without antecedents are sometimes called unprecursed pronouns.) Another type of antecedent is that found with relative pronouns, as in the woman who looked at you, where the woman is the antecedent of the relative pronoun who.