sincerely

Sincerely is an adverb with two principal uses. It can express genuineness or earnestness, as in “I sincerely apologize” or “We sincerely appreciate your support.” It is also a conventional closing in written correspondence, appearing in forms such as “Sincerely,” or “Sincerely yours,” to indicate polite regard from the writer.

Origin and form: The word derives from the adjective sincere, from Latin sincerus meaning pure, clean, sound. Sincere appeared in English in the Middle Ages, and sincerely as an adverb developed from the adjective to form “sincerely” in the early modern period. The sense of honesty and earnestness anchors most current uses.

Usage in writing: In letter-writing, closings vary by tradition. In British English, “Yours sincerely” is used when the writer knows the recipient’s name, and “Yours faithfully” when the name is not known. In American English, “Sincerely” is common, often followed by a comma or paired with “yours,” as in “Sincerely yours.” In modern emails, closings such as “Sincerely” or “Best regards” are widely used, with formality often guiding the choice.

Semantic notes: As an adverb, sincerely is used to modify verbs or clauses that express belief, hope, or apology, e.g., “I sincerely hope the proposal is approved.” The core idea is honesty and earnest intent; related terms include sincerity (the noun) and sincere (the adjective).