According to the classic definition, a pronoun is a word used in place of a noun. However, some pronouns work like adjectives, modifying the meaning of a noun. But while an adjective may modify or limit the meaning of a noun in a novel way, creating, just possibly, a subset of the class of nouns that has never been spoken of before (e.g. "a transcendental cow," "a nuclear teapot"), the adjectival pronoun modifies the sense of the noun by widening or narrowing its reference in a very limited and stereotyped way: "this cow" (the one here with me), "each teapot" (all of them, but considered one by one). The adjectival pronoun can quite generally be used as a "classic" pronoun, standing in for a noun rather than modifying one ("Have you seen this?" "I have heard the mermaids singing, each to each").

Whether pronouns like this, that and each should be called adjectives when used with nouns is a matter best left to the theoreticians. Old English scholars generally call them pronouns to avoid getting knotted up over one very large class of them, namely the demonstrative pronouns which in Old English are used where Modern English uses the adjective-like "article," the. In Modern English the "article" can hardly be confused with the demonstrative pronoun that, though their functions are similar; but Old English made no formal distinction between them. Thus you may translate se cyning as "the king" or as "that king," depending on the context.

Pronouns are of seven types: personal, demonstrative, interrogative, indefinite, relative, reflexive, and reciprocal. Some classify as pronouns the possessives which are inflected like adjectives, but Old English Aerobics (perhaps rather arbitrarily) classifies these as adjectives. Here is a rundown of the types:

When a pronoun has an antecedent (a noun it refers back to), it must agree with that antecedent in gender and number. This rule can produce some disconcerting effects for the modern reader. For example, when we read of the sun, æfre heo tyrnð onbutan us, the pronoun heo looks to us as if it should be translated "she." But heo is referring to feminine sunne and must be translated "it": "it is always turning around us."