English in Use/Punctuation

Punctuation is the art of dividing literary composition, by points, or stops, for the purpose of showing more clearly the sense and relation of the words; and of noting the different pauses and inflections required in reading.
The following are the principal points, or marks:
The comma denotes the shortest pause; the semicolon, a pause double that of the comma; the colon, a pause double that of the semicolon; and the period, or full stop, a pause double that of the colon. The pauses required by the other four, vary according to the structure of the sentence, and their place in it. They may be equal to any of the foregoing.
Comma.
The comma is used to separate those parts of a sentence, which are so nearly connected in sense, as to be only one degree removed from that close connection which admits no point.
Simple sentences.
A simple sentence does not, in general, admit the comma: as,
Nominative accompanied by adjuncts.
When the nominative in a long simple sentence is accompanied by inseparable adjuncts, or when several words together are used instead of a nominative, a comma should be placed immediately before the verb: as,
Simple members.
The simple members of a compound sentence, whether successive or involved, elliptical or complete, are generally divided by the comma: as,
Relative that follows its antecedent.
When a relative immediately follows its antecedent, and is taken in a restrictive sense, the comma should not be introduced before it: as,
Closely connected simple members.
When the simple members are short, and closely connected by a conjunction or a conjunctive adverb, the comma is generally omitted: as,
Simple immediately united members.
When two simple members are immediately united, through ellipsis of the relative, the antecedent, or the conjunction that, the comma is not inserted: as,
More than two words.
When more than two words or terms are connected in the same construction, or in a joint dependence on some other term, by conjunctions expressed or understood, the comma should be inserted after every one of them but the last; and, if they are nominatives before a verb, the comma should follow the last also: as,
Only two words.
When only two words or terms are connected by a conjunction, they should not be separated by the comma: as,
Two words with several adjuncts.
When the two words connected have several adjuncts, or when one of them has an adjunct that relates not to both, the comma is inserted: as,
Contrasted words or phrases.
When two connected words or phrases are contrasted, or emphatically distinguished, the comma is inserted: as,
Alternative of names.
When there is merely an alternative of names, or an explanatory change of terms, the comma is usually inserted: as,
Understood conjunction.
When the conjunction is understood, the comma is inserted; and, if two separated words or terms refer alike to a third term, the second requires a second comma: as,
Words in pairs.
When successive words are joined in pairs by conjunctions, they should be separated in pairs by the comma: as,
Words put absolute.
Nouns or pronouns put absolute, should, with their adjuncts, be set off by the comma: as,
Appositions or appositives.
Words in apposition, especially if they have adjuncts, are generally set off by the comma: as,
A compound name.
When several words, in their common order, are used as one compound name, the comma is not inserted: as,
United common and proper name.
When a common and a proper name are closely united, the comma is not inserted: as,
A mere emphasis and distinction.
When a pronoun is added to an other word merely for emphasis and distinction, the comma is not inserted: as,
Name acquired by action or relation.
When a name acquired by some action or relation, is put in apposition with a preceding noun or pronoun, the comma is not inserted: as,
Adjectives.
Adjectives, when something depends on them, or when they have the import of a dependent clause, should, with their adjuncts, be set off by the comma: as,
Adjective which follows its noun.
When an adjective immediately follows its noun, and is taken in a restrictive sense, the comma should not be used before it: as,
Finite verbs.
Where a finite verb is understood, a comma is generally required: as,
A pause for the omitted verb.
As the semicolon must separate the clauses when the comma is inserted by this rule, if the pause for the omitted verb be very slight, it may be left unmarked, and the comma be used for the clauses: as,
Infinitives.
The infinitive, when it follows a verb from which it must be separated, or when it depends on something remote or understood, is generally, with its adjuncts, set off by the comma: as,
Participles.
Participles, when something depends on them, when they have the import of a dependent clause, or when they relate to something understood, should, with their adjuncts, be set off by the comma: as,
Participle which follows its noun.
When a participle immediately follows its noun, and is taken in a restrictive sense, the comma should not be used before it: as,
Adverbs.
Adverbs, when they break the connection of a simple sentence, or when they have not a close dependence on some particular word in the context, should, with their adjuncts, be set off by the comma: as,
Conjunctions.
Conjunctions, when they are separated from the principal clauses that depend on them, or when they introduce examples, are generally set off by the comma: as,
Prepositions.
Prepositions and their objects, when they break the connection of a simple sentence, or when they do not closely follow the words on which they depend, are generally set off by the comma: as,
Interjections.
Interjections that require a pause, though more commonly emphatic and followed by the ecphoneme, are sometimes set off by the comma: as,
Words emphatically repeated.
A word emphatically repeated, is generally set off by the comma: as,
Dependent quotations.
A quotation, observation, or description, when it is introduced in close dependence on a verb, (as, say, reply, cry, or the like,) is generally separated from the rest of the sentence by the comma: as,
Semicolon.
The semicolon is used to separate those parts of a compound sentence, which are neither so closely connected as those which are distinguished by the comma, nor so little dependent as those which require the colon.
Complex members.
When two or more complex members, or such clauses as require the comma in themselves, are constructed into a period, they are generally separated by the semicolon: as,
Simple members.
When two or more simple members, or such clauses as complete their sense without subdivision, are constructed into a period; if they require a pause greater than that of the comma, they are usually separated by the semicolon: as,
Apposition.
Words in apposition, in disjunct pairs, or in any other construction, if they require a pause greater than that of the comma, and less than that of the colon, may be separated by the semicolon: as,
Colon.
The colon is used to separate those parts of a compound sentence, which are neither so closely connected as those which are distinguished by the semicolon, nor so little dependent as those which require the period.
Additional remarks.
When the preceding clause is complete in itself, but is followed by some additional remark or illustration, especially if no conjunction is used, the colon is generally and properly inserted: as,
Greater pauses.
When the semicolon has been introduced, or when it must be used in a subsequent member, and a still greater pause is required within the period, the colon should be employed: as,
Independent quotations.
A quotation introduced without a close dependence on a verb or a conjunction, is generally preceded by the colon: as,
Period.
The period, or full stop, is used to mark an entire and independent sentence, whether simple or compound.
Distinct sentences.
When a sentence, whether long or short, is complete in respect to sense, and independent in respect to construction, it should be marked with the period: as,
Allied sentences.
The period is often employed between two sentences which have a general connection, expressed by a personal pronoun, a conjunction, or a conjunctive adverb: as,
Abbreviations.
The period is generally used after abbreviations, and very often to the exclusion of other points; but, as in this case it is not a constant sign of pause, other points may properly follow it, if the words written in full would demand them: as, A. D. for Anno Domini; Pro tem. for pro tempore; Ult. for
ultimo; i.e. for id est, that is;
Dash.
The dash is mostly used to denote an unexpected or emphatic pause, of variable length; but sometimes it is a sign of faltering, or of the irregular stops of one who hesitates in speaking: as,
Abrupt pauses.
A sudden interruption, break, or transition, should be marked with the dash: as,
Emphatic pauses.
To mark a considerable pause, greater than the structure or the sentence or the points inserted would seem to require, the dash may be employed: as,
Faulty dashes.
Dashes needlessly inserted, or substituted for other stops more definite, are in general to be treated as errors in punctuation: as,
If this colon is sufficient, the capital after it is needless: a period would, perhaps, be better.
Note of interrogation.
The eroteme, or note of interrogation, is used to designate a question.
Questions direct.
Questions expressed directly as such, if finished, should always be followed by the note of interrogation: as,
Questions united.
When two or more questions are united in one compound sentence, the comma, semicolon, or dash, is sometimes used to separate them, and the eroteme occurs after the last only: as,
Questions indirect.
When a question is mentioned, but not put directly as a question, it loses both the quality and the sign of interrogation: as,
Note of exclamation.
The ecphoneme, or note of exclamation, is used to denote a pause with some strong emotion of admiration, joy, grief, or other feeling; and, as a sign of great wonder, it is sometimes, though not very elegantly, repeated: as,
Interjections.
Emphatic interjections, and other expressions of great emotion, are generally followed by the note of exclamation: as,
Invocations.
After an earnest address or solemn invocation, the note of exclamation is now generally preferred to any other point: as,
Exclamatory questions.
Words uttered with vehemence in the form of a question, but without reference to an answer, should be followed by the note of exclamation: as,
Curves.
The curves, or marks of parenthesis, are used to distinguish a clause or hint that is hastily thrown in between the parts of a sentence to which it does not properly belong: as,
The incidental clause should be uttered in a lower tone, and faster than the principal sentence. It always requires a pause as great as that of a comma, or greater.
Parenthesis.
A clause that breaks the unity of a sentence or passage too much to be incorporated with it, and only such, should be inclosed within curves, as a parenthesis: as,
Included points.
The curves do not supersede other stops; and, as the parenthesis terminates with a pause equal to that which precedes it, the same point should be included, except when the sentences differ in form: as,
Apostrophe.
The apostrophe usually denotes either the possessive case of a noun, or the elision of one or more letters of a word: as,
'Gan, lov'd, e'en, thro'; for began, loved, even, through. It is sometimes used in pluralizing a mere letter or sign: as,
Hyphen.
The hyphen connects the parts of many compound words, especially such as have two accents: as, ever-living. It is also frequently inserted where a word is divided into syllables: as, con-tem-plate. Placed at the end of a line, it shows that one or more syllables of a word are can led forward to the next line.
Diaeresis.
The diaeresis, or dialysis, placed over either of two contiguous vowels, shows that they are not a diphthong: as, "Danaee, aerial".
Acute accent.
The acute accent marks the syllable which requires the principal stress in pronunciation: as, e'qual, equal'ity. It is sometimes used in opposition to the grave accent, to distinguish a close or short vowel: as, "Fancy"; or
to denote the rising inflection of the voice: as,
Grave accent.
The grave accent is used in opposition to the acute, to distinguish an open or long vowel: as, "Favour"; or to denote the falling inflection of the voice: as,
It is sometimes placed over a vowel to show that it is not to be suppressed in pronunciation: as,
Circumflex.
The circumflex generally denotes either the broad sound of a or an unusual sound given to some other vowel: as in all, heir, machine. Some use it to mark a peculiar wave of the voice, and when occasion requires, reverse it: as,
Breve.
The breve, or stenotone, is used to denote either the close, short, shut sound of a vowel, or a syllable of short quantity: as, lĭve, to have life; răven, to devour; călămŭs, a reed.
Macron.
The macron, or macrotone, is used to denote either the open, long, primal sound of a vowel, or a syllable of long quantity: as, līve, having life; rāven, a bird; ēquīne, of a horse.
Ellipsis.
The ellipsis, or suppression, denotes the omission of some letters or words: as, K…g, for King; c…d, for coward; d…d, for damned.
Caret.
The caret, used only in writing, shows where to insert words or letters that have been accidentally omitted.
Tilde.
The tilde, "ã", is a diacritic mark, and tilde over a letter is used to make abbreviations.
Brace.
The brace serves to unite a triplet; or, more frequently, to connect several terms with something to which they are all related.
Section.
The section marks the smaller divisions of a book or chapter; and, with the help of numbers, serves to abridge references.
Paragraph.
The paragraph denotes the commencement of a new subject. The parts of discourse which are called paragraphs, are, in general, sufficiently distinguished by beginning a new line, and carrying the first word a little forwards or backwards. The paragraphs of books being in some instances numbered, this character may occasionally be used, in lieu of the word paragraph, to shorten references.
Quotation points.
The guillements, or quotation points, distinguish words that are exhibited as those of an other author or speaker. A quotation within a quotation, is usually marked with single points; which, when both are employed, are placed within the others: as,
Brackets.
The crotchets, or brackets, generally inclose some correction or explanation, but sometimes the sign or subject to be explained: as,
Index.
The index, or hand, points out something remarkable, or what the reader should particularly observe.
Asterisk.
The asterisk, or star, the obelisk, or dagger, the diesis, or double dagger, the section, the parallels, and the paragraph, refer to marginal notes. Where many references are to be made, the small letters of the alphabet, or the numerical figures, in their order, may be conveniently used for the same purpose.
Asterism.
The asterism, or three stars, a sign not very often used, is placed before a long or general note, to mark it as a note, without giving it a particular reference.
Cedilla.
The cedilla is borrowed from the French. It is placed under the letter "c", to give it the sound of "s", before "a" or "o": as, "Façade", "Alençon". It is sometimes attached to other letters, to denote their soft sounds: Ģ as "J"; Ş as "Z".