Whereof

Whereof is an archaic and formal English pronoun meaning "of which" or "of what," used to refer back to something previously mentioned. It often introduces a relative clause or a prepositional phrase and typically follows a noun such as matter, thing, reasons, or terms.

Etymology traces whereof to Old English, combining where (in reference to a topic or place) with of. It was common in Early Modern English and remains visible in the works of Shakespeare and the King James Bible, where the cadence and grandeur of the language are preserved through such forms.

Modern usage and style considerations: whereof is largely obsolete in everyday speech and contemporary prose. It persists in historical writing, ceremonial or religious texts, and some legal or quasi-legal drafting where a formal or archaizing tone is desired. When clarity is paramount, writers usually substitute phrases like "of which," "to which," or "about which," selecting the version that matches the intended relationship.

Examples and equivalents: The reasons whereof I speak are set forth in the appendix. The terms whereof are defined in section 3. For modern alternatives, one would say: The reasons that I am speaking of are set forth in the appendix, or The terms defined in section 3.

In summary, whereof is a stylistic relic of English that can be used for effect in selective contexts, but it is generally replaced by more straightforward forms in contemporary writing.