Punctuation. The discriminating use of certain marks adopted to distinguish the clauses of a period, sometimes with reference to the sense, and at others to the grammatical construction. Thus, a full point (. ) closes a perfect sentence; a colon (:) indicates an adjunct; a semicolon (;) distinguishes its principal part, and a comma (,) parts subordinate to the semicolon. A sentence, which may include several periods, terminates a branch of the subject or argument. A dash ( - ) within a period, calls for attention to what follows, and a series of dashes indicates the energetic feeling of the writer. A question is indicated by (?) ; an exclamation by (!); and it is sometimes convenient to include a collateral circumstance in a parenthesis ( ).