Bonjour Stuart, Lui is two different kinds of pronouns. When it's a stressed pronoun, it only means him, because there's a feminine stressed pronoun: elle. Lesson: Moi, toi, lui, elle, nous, vous, eux, elles (advanced stress pronouns) When it's an indirect object pronoun, it can mean him or her because there is no separate feminine pronoun. Lesson: Replacing people with lui, leur = him, her, them (indirect object pronouns) In "I speak of her," her is the object of the pronoun of and therefore must be translated by the stressed pronoun elle, not the indirect object lui.