Punctuation in English

Types of punctuation marks

.		period / full stop
:		colon
;		semicolon
a-b		hyphen
a – b		dash (depending on length: en dash or em dash)
(ab)		parentheses, sg. parenthesis
[ab]		(square) brackets
a’b		apostrophe, pl. apostrophes
“ab”		quotation marks (or: quote marks, speech marks, inverted commas)
...		ellipsis, pl. ellipses (or: suspension point; informally: dot-dot-dot)
?		question mark
!		exclamation point (or: mark)
/		slash, pl. slashes (or: stroke)

Further punctuation marks include the at sign (@), the ampersand (&), the asterisk (*), the backslash (\).

Periods

• No period is needed in abbreviations if the last letter of the abbreviation is the last letter of the word: St, Rd ...
• Periods, and not commas, are used as decimal points: an average temperature of 20.5°C, at a price of €45.12, 23.4% of all voters ...
• No periods are needed for metric abbreviations (cm, mm, l, g, kg), U.S. state abbreviations (OR, TX, MN) and a few other abbreviations (NATO, NRA, ACLU...).
• If a sentence closes with an abbreviation that requires a period, there is no need of yet another period: He woke up at 6:30 a.m.

Question marks

• Not question marks but periods are used in indirect questions: He wanted to know whether everything was fine.
• In quotations, the basic question is: Is the question mark part of the quotation or not? If yes, it will be included in the quoted text: The assembly was unsure how to answer the question,“Is Crimea part of Russia or not?” If not, it will follow the quoted text: What is this supposed to be, “democracy”? If the question appears in a quote in the middle of a sentence, the question mark will precede the closing quotation mark: Asking a question like “Who is to blame?” is not always the best way to settle a conflict.
• Question marks are frequently used to indicate that a date or number may not be accurate or disputed: Walther (1205?–1253) is said to have lived near Cologne.

Exclamation marks (or: exclamation points)

• Exclamation points denote strong emotions. Don’t use too many exclamation marks in your writing.
• Exclamation points are often used to express emphasis: Oh, light! Run! Loser! If your interjection is not meant to be emphatic, use commas: Caesar died 44 BC, yes, but this was not the end of an era.
• In quotations, exclamation points follow the same rules as question marks (see above).

Commas

• Commas are used to link lists of items, groups of words, adjectives, actions, adverbs.
• There is no comma before the last item of a list if there is a conjunction.
• Commas in dialogues are used to
• separate dialogue from the rest of the sentence: Johnson said, “I won’t be able to help you.”
• to address people: Mike, I need your help. – No, Johnson, I don’t see what you’re getting at.
• when “yes” and “no” form part of an answer: Yes, I see.
• in interjections: Oh, imagine that!
• to introduce quotations: He said, “There’s no need to hurry.
• to separate question tags from the main clause: You’ll be home tonight, won’t you?
• They are often used in dates: January 2^nd, 1876 ...
• Commas are used in numbers after each group of three figures: 345,000,000 ...
• You also use them to separate numbers that occur immediately after another: On March 14, 789 people got killed.
• Commas should be used with personal titles:VC Singh, principal of Rawal International School, pointed out that...
• Commas are used with place names – so, place a comma between street addresses, city names, state names, and countries: He comes from Sublimity, Marion County,
• Commas separate the main clause and the subordinate clause to help the reader understand your sentence: When I came in, everybody burst with laughter.
• Commas are used to emphasize contrast: Mark was hungry, and Tom was not.
• Commas are used for asides that give the reader additional information: Liza, having said that, left the room.
• Commas can be used to mark parenthetical expressions: All the senior students, much to their teachers’ surprise, handed in their essays by Friday.
• Commas are not needed with restrictive modifiers – that is, relative clauses with “that” and “which” that provide additional information: I bought a new laser pointer _ which is rather easy to handle.
• Whenever a “which” clause serves as a nonrestrictive modifier, use commas: Students never keep their smartphones off during lessons, which makes it extremely difficult for them to follow the lesson.
• Commas separate adverbial phrases from the main clause: Luckily, I had saved all my files before the computer crashed. – You offer is very tempting, however, I cannot take it.
• Commas are not used with “of course” and “nevertheless”: Of course _ I’ll do that. – We’ll meet him _ nevertheless.
• Commas should be used to separate a long introductory modifier from the main clause: Even though he had not been able to finish his essay on time, it was still good.
• Commas can be used to separate main clauses after coordinating conjunctions (or, and, but) if each sentence has enough weight to work as an independent sentence: He was not able to come to class on Saturday, and it made him feel miserable.
• However, don’t separate two verbs with the same subject. Tom received the assignment on Tuesday _ and promised to complete it by Thursday.
• Don’t use commas to separate a main clause from a restrictive clause.He cannot finish the corrections _ while his wife is still in hospital. – He gave his students some extra work _ in order to prevent further disciplinary problems.
• Commas should not be used to separate a “because clause” from a main clause: She consulted the school counsellor _ because it seemed to be a rather complex problem.
• Use commas with nonrestrictive clauses that occur within a “that” clause: He suggested that, in spite of all the problems that had occurred, he could still be promoted.
• In absolute phrases, use commas. Absolute phrases consist of a noun or pronoun and a participle: Having said that, he left the room.
• In a list, use commas between the last two items to make things clearer: I met my old teacher, Mr Delanay, and the principal. > Here, the teacher’s name is Delaney. - I met my old teacher, Mr Delanay and the principal. > Here, Mr Delaney is another person in the list.
• Use commas with coordinate adjectives – coordinate adjectives can be reversed in order (energetic, lively students). Don’t use commas with cumulative adjectives; if adjectives describe one another, you don’t need a comma: delicious _ Italian ice cream.
• Use commas to set off quotations from a speaker: “Damn it”, said Jones.
• Don’t use commas with quotations that are exclamations or questions: “Where is he?” _ said Jones.
• Don’t use commas before “than”: Studying with a classmate is not always more effective _than working on your own.
• Don’t place commas between subjects and predicates: Several of the other teachers _ criticized the vice principal.
• Don’t use commas after a subordinating conjunction such as “although”, “despite of”, or “while”: Although _ he thought he was well prepared, he failed the test.

Semicolons

• Semicolons can be used to join main clausesthat are logically connected: Hermann Hesse had a miserable childhood; he even asked his father to send him a revolver.
• They also replace commas after certain transitional wordsand phrases: World literature is full of authors with drinking problems; however, this has not always been noticed. Some of these phrases are: furthermore, however, moreover, nonetheless, in fact, for instance, in addition, thus, in other words ...
• Semicolons are not used to introduce lists or quotations; here, colons should be used.
• Semicolons can help to structure lists that contain various elements combined of two items: The guest list included several international visitors: Bob Myers, Canada; Alvaro Sanchez, Costa Rica; Ibrahim Traoré, Burkina Faso.

Colons

• Use colons to introduce lists: Several Irish writers were awarded the Nobel Prize: Seamus Heaney, William Butler Yeats, and Samuel Becket, to name only three of them. However, colons can only be placed after a clause that can stand by itself as a sentence.
• Colons can be used to introduce an interpretation or summary: There is only one reason why the Mongols didn’t invade Central Europe: the Black Death.
• Colons can be used to introduce an appositive, a phrase that renames the noun preceding it: I can think of only one person who could have said this: you!
• Use colons to introduce a quotation: Those were the words Churchill had repeated so many times: “No surrender!”

Hyphens

Hyphenate...

• prefixes when used with a capitalized noun or adjective: un-American, de-Stalinisation ...
• acronyms that are part of a compound modifier: anti-NATO attitude, non-SI units ...
• to clarify themeaning of words that look similar: The clouds re-formed after the storm . – The legal system needs to be reformed.
• when letters in a newly formed compound would otherwise be doubled or tripled: anti-inflammatory, shell-like ...
• phrases when they are used as modifiers preceding nouns: step-by-step instructions, an all-or-nothing decision.
• to differentiate compound modifiers from two adjacent modifiers that modify the noun independently, unless capitalization or italicization makes grouping clear: small appliance industry = a small industry producing appliances; small-appliance industry = an industry producing small appliances.
• adjectives preceding a noun to which “-d” or “-ed” has been added as a past-participle construction, used before a noun: middle-aged lady, one-armed bandit ... ;however, don’t hyphenate left-hand components of a compound modifier that end in “-ly” and that modify right-hand components that are past participles (ending in -ed): a hotly disputed subject, a greatly improved scheme ...
• nouns, adjectives, or adverbs preceding a present participle: a far-reaching decision, a long-lasting relationship ...
• numbers, whether or not spelled out, that precede a noun: a 7-year-old boy, a nineteenth-century poem ...; numerals with the suffix “-fold”, but not if it is spelled out: 7-fold ... , but: sevenfold; numerals with “-odd”: 20-odd ...
• compound modifiers with “high-“ or “low”-: high-level discussion, low-price markup...
• compounds including colors: dark-green jacket, blue-colored car ...
• fractions as modifiers: two-thirds of the population ... , but if numerator or denominator are already hyphenated, the fraction itself does not take a hyphen: an eighty-five thousandth part of a millimeter ...
• comparatives and superlatives incompound adjectives: the highest-placed competitor, a shorter-term loan ... ; but not constructions with “most”: the most respected member ... ; also, don’t hyphenate compound modifiers that include comparatives and superlatives with “more”, “less” or “least!”; don’t hyphenate compounds with intensive adverbs in front of adjectives that would regularly be hyphenated: very much admired violinist, really well accepted proposal ...
• compounds including two geographical modifiers: Anglo-Indian, German-American ... ; but not modifiers that refer to specific regions: South American politician ...

Dashes

• In typography, there are actually two dashes: the en dash and the em dash, named after the space normally taken by the letters “n” or “m”.
• A dash denotes a break in a sentence or to set off parenthetical statements, replacing parenthesis or commas and colons or semicolons: There was only one bully in his class – John. - His biggest problem – besides his grades – were his debts with John.
• A dash replaces “and” or “to” (but not “to” in the phrase “from … to …”: William Shakespeare (1564–1616) was born in Stratford-upon-Avon. But: Shakespeare lived from 1564 to1616.)
• In rare cases, dashes are used replace hyphens to avoid ambiguity and for clarification in constructions with two hyphened items: non–self-governing, the in-group–out-group problem ...
• In dialogue, dashes can be used to indicate a speaker has been interrupted, also, if the other speaker completes the other speaker’s sentence: “But I told you he would never – – ““Listen, of course he wouldn’t release his hostages.” Sometimes, the speakers’ contributions in a dialogue are preceded by dashes as well, indicating a change in turns.
• Two figures of speech also come along with dashes: correction(“She was his second – no, his first wife.”) and aposiopesis (“Stop that, or else –“).
• A dash is also used to indicate that letters have been omitted deliberately: He kept swearing about his brother’s “f – cking” car.

Parentheses and (square) brackets

• Among the types of brackets that exist, there is a number of special forms, most notably angle brackets or chevrons and curly brackets. As for now, let us focus on parenthesis and square brackets.
• Parentheses serve to clarify that something is said aside from the main point: I have postponed the exam (I wonder whether you’ve heard about it) and will make it a bit more difficult.
• In a formal context, they may also be used to add supplementary information: The German Chancellor Angela Merkel (CDU) pointed out that ... .
• Sometimes, parenthesis is also used to shorten grammatical constructions as in gender-neutral diction: the contract(s) – A patient has to be informed if (s)he ... .
• Parentheses usually indicate in-text citations: This has been observed among bonobos just as well as with gorillas (Goodall, 1987).
• If the bracketed element stands within a sentence, the commas, colons, semicolons and period will follow the closing bracket: He missed Roger (the duck), but he fired at it several times (at least twice).
• Also, whenever a sentence is enclosed in parentheses, the period must be placed before the closing parenthesis: English is a lingua franca. (It’s in fact a lingua franca to be used all over the world.)
• Parentheses may be nested; while parentheses are used on the primary level, square brackets are used on the secondary level, the tertiary level comes in curly or, again,  round brackets: This sentence (as we may call it a sentence [“sentence” (Smith 2004, p. 7)]) doesn’t really make sense.
• Parentheses may help to structure lists: There are three main skills that need to to be addressed in every English class, (1) reading, (2) writing) and (3)
• Square brackets are mostly used to indicate omitted material or additional material necessary to make a quote work in its grammatical context: Trump pointed out he would “never [...] resign”. – Trump pointed out “it [the press release] was all fake news”.
• The bracketed expression “[sic]” indicates that there is a problem in the quote the reader is warned not to overlook: As the secretary of state had stated earlier, she believed that “Danemark [sic] is just a very small and insignificant socialist country”.

Apostrophes

• Apostrophes indicate the genitive (or possessive) case: John’s car, Felix’s girlfriend, Francis’s lover ...
• However, there are a few exceptions where adding -’s is avoided to facilitate pronunciation (Herodotus’ travels, Jesus’ death ..) or because the possessive case is part of a proper name (Governors Island, Borders Bookstore ... ). The latter is very common with American and Australian geographical names and much less so in the United Kingdom.
• For plural names that do not require -s, add -’s: women’s clothing, media’s interest, children’s behavior ...
• For plural names that regularly end with an -s, simply add the apostrophe: the Millers’ house, the Joneses’ ..
• For compound nouns, only add an -’s to the last part: the King of Scotland’s men, my sister-in-law’s carpet ... .
• If there are two or more people that own the same item, add an -’s to the last part: Tom and Jeremy’s friend Marcus, Layla and Fred’s Diner ...
• If there are two or more people who possess things separately, add an -’s to all parts: Linda’s and Richard’s views couldn’t differ more. - Both Fred’s and Suzi’s parents were rather unhappy about their children’s wedding.
• Never add an apostrophe to possessive forms of personal pronouns: The dog sat on its - The robot was detected due to its strange sounds. Also, add an apostrophe to nouns simply to produce plural forms – superfluous apostrophes in forms like “strawberry’s” are referred to as greengrocers’ apostrophes.
• Apostrophes also indicate contractions (she will > she’ll, he does not > he doesn’t), abbreviations (government > gov’t, especially in British road signs: W’hampton, K’minster) and in omissions (the 1980s > the ’80s, rock and roll > rock ’n’ roll, neighborhood > ’hood).
• The plural forms of numbers and acronyms don’t take an apostrophe: the 1760s, no VIPs, the tens and hundreds ...
• The plural of symbols as well as letters and words (as grammatical units or parts of a text) do also take the apostrophe: The #’s and the +’s must be omitted, also the m’s and if’s.
• In rare cases, verbs may take an apostrophe in their past tense forms: to KO someone > he got KO’d ...
• The apostrophe may also occur in Irish and Scottish surnames (O’Malley, M’Intosh ... ) or in transliterated words from other languages (Qu’ran, Xi’an ... ).

Quotation marks

• Quotation marks enclose direct quotations, but not paraphrases and indirect quotations: The words “No sports!” are commonly attributed to Winston Churchill. – Churchill has stated on various occasions he didn’t approve of sports.
• Quotation marks are not used with block quotations set off from the rest of the text.
• Quotation marks can also be used to enclose direct speech in a dialogue: “For a reason”, said Lisa.
• Titles of shorter works of literature and films may also be enclosed in quotation marks: short stories, articles from magazines and newspapers, essays, songs and poems, speeches of all genres, chapters, short films, documentaries and television or radio shows.
• Quotations marks can also indicate novel words: The Surrealists referred to these works as “automatic paintings”.
• Also, quotation marks can be used to indicate that words are used as lexemes in a given context: He found it difficult to explain the difference between “its” and “it’s”.
• Quotation marks should not be used to acknowledge the use of a cliché, to express emphasis or to indicate irony: The conference was very “entertaining”.
• If there is a quote within another quote, use single quotation marks: While Clint Eastwood “has always been what he called himself an ‘anti-gun lobbyist’”, many people still see him as an advocate of the NRA.
• Colons and semicolons that follow a sentence in a quotation will be placed after the closing quotation mark: “The army of Mark Anthony had been crushed by Caesar’s men;” this statement indicates a strong bias against the latter. As for exclamation points, dashes and question marks, see the respective article above.
• Guillemets (« … ») can sometimes also be found instead of quotation marks, especially in fiction.
• In longer quotes, especially in literary works, you normally give opening quotation marks to the first and each of the following paragraphs, using closing quotation marks only for the final paragraph of the quotation.
• Quotation marks can also be used to offset a nickname or false title: William “Wild Bill” Cody, Nat “King” Cole ...

Ellipsis

• Ellipsis can be used to indicate omitted words in a quotation: He was (at least on Sundays) always late. > According to Johnson, “[h]e was ... always late”.
• Ellipses can also indicate that a speaker takes a long pause: Let me think ... oh, yes, I’ve seen him!
• Like dashes, ellipses can indicate that the speaker has been interrupted or didn’t deliberately finish the sentence: Watch out, the piano is ... !
• An ellipsis should never be preceded or followed by a full stop.
• In literature, ellipsis can be used to indicate intentional silence or to make the reader think about the last points in the text.

Slashes (or: Strokes)

• Slashes are used to connect alternatives. Do not put spaces between the alternatives and the slash: on/off switch, actor/director ...
• The same rule applies to fractions. No spaces required: 3/4, 7/..
• In an informal context, slashes are also common in dates: Actually, 18/10/18 is already booked.
• In quotes from poetry, a slash indicates a line break: “For oft, when on my couch I lie / In vacant or in pensive mood”.
• Slashes are also used in inclusive writing separating the genders: He / She should proceed with caution.