Punctuation, in grammar, the art of dividing a written or printed discourse into sentences and parts of sentences, for the purpose of indicating the mutual relations of the words, by means of points. The principal points used in English composition are the comma (,), semicolon (;), colon (:), period (.), note of interrogation (?), note of exclamation or admiration (!), dash ( - ), and parenthesis (). Of these, only the first four are marks of punctuation as the term is usually understood, or grammatical points indicating the length and character of the pauses to be made in reading. The others are mainly rhetorical or syntactical aids, regulating the modulation of the tone rather than the suspension of the voice; but the interrogation or exclamation point may take the place of either of the former, according to the structure of the sentence, and the dash partakes of both characteristics. The comma marks the smallest grammatical division in written or printed language. The semicolon separates such parts of a sentence as are somewhat less closely connected than those separated by a comma. The colon denotes a still longer pause than the semicolon.

The period indicates the end of an assertive sentence which is grammatically independent of any that follows, and is also used after every abbreviated word, after headings, titles of books, etc, and generally (though improperly) after Roman numerals. The note of interrogation is placed after a question, and in Spanish is also placed inverted at the beginning of a question. The note of exclamation indicates an ardent wish, admiration, or other strong emotion, and is placed after interjections, words used as interjections, and clauses or sentences expressing strong emotion of any. kind; it is also duplicated in Spanish like the preceding. The dash is employed where a sentence breaks off abruptly and the subject is changed; where the sense is suspended, and is continued after a short interruption; where there is an unexpected or epigrammatic turn in the sentiment; after a long member, or series of phrases or clauses, leading to an important conclusion; before a word or phrase repeated in an exclamatory or emphatic manner - what elocutionists term an echo; where there is an ellipsis of such words as "namely" and "that is;" where there is an ellipsis of letters or figures; and in numerous other cases. Sometimes, as in this work, it is used instead of paragraphs.

The parenthesis encloses a word or phrase introduced into the body of a sentence with which it has no grammatical connection, or an explanatory or other sentence or passage independent of the context. - Other marks in frequent use, and generally treated under the head of punctuation, though not strictly included in it, are the apostrophe ('), used to indicate the omission of a letter or letters, and also as a sign of the possessive case; the hyphen (-), placed between the constituent parts of a compound word, and at the end of a line when a word is divided; quotation marks (" " or ' '), placed at the beginning and end of extracted passages, of the speeches in dialogue, etc.; brackets or crotchets [ ], generally enclosing an explanatory phrase or passage inserted by one writer in a quotation from another; and references (consisting of the characters *, †, ‡, §, ║, and ¶, called respectively asterisk or star, dagger, double dagger, section, parallel, and paragraph, or of figures or letters smaller than those of the text), pointing to notes correspondingly marked at the foot or margin of the page. - The ancients were in the habit of writing without distinction of either sentences or words until about 364 B. C. Afterward it became usual to place a mark of distinction at the end of every word, as in the following inscription found near Bath, England:

Ivlivsv Vitalisv Fabri, Etc

Sometimes, as in the subjoined extract from an inscription given by Montfaucon, a letter laid horizontally was used as an interstitial mark:

P. FERRARIVS HERMES CAECINIAE Punctuation 140059 DIGNAE CONIVGI Punctuation 140060 KARISSIMAE NVMERIAEPunctuation 140061 .

But there is reason to believe that some system of punctuation was known to the Greeks in the time of Aristotle. It probably consisted of a single mark, which changed its signification according to a change of position. At the bottom of a letter (A.) it was equivalent to a comma; in the middle (A.), to a colon; and at the top (A.), to a period; but this plan could only be followed as long as Greek manuscripts were written entirely in capitals. St. Jerome in his translation of the Scriptures used certain marks of distinction or division, which he called commata and cola; but it has been thought that they consisted simply in writing every clause on a separate line. The modern points came into use very gradually after the invention of printing, the comma, parenthesis, note of interrogation, and period being the earliest introduced, and the note of exclamation the last. The first printed books have only arbitrary marks here and there, and it was not until the 16th century that an approach was made to a regular system by the Manutii of Venice.