English (United States) typography rules · en-US
English (United States)
English (United States) sets primary quotation marks as “…” and secondary quotation marks as ‘…’. A break in a sentence is written with an em dash (U+2014) with no surrounding spaces; number and date ranges take an en dash (U+2013) with no surrounding spaces. Numbers bind to units such as % kg g with U+00A0.
Run polytypo with English (United States) rules
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English (United States) typography at a glance #
| Tag | en-US |
|---|---|
| Name | English (United States) |
| Primary quotes | “ U+201C left double quotation mark … ” U+201D right double quotation mark |
| Secondary quotes | ‘ U+2018 left single quotation mark … ’ U+2019 right single quotation mark |
| Parenthetical dash | unspaced em dash |
| Range dash | unspaced en dash |
| Rules with citations | quotes, dashes, ellipsis, nbsp, hyphen |
| Conformance cases | 432 |
Which locale tags resolve to English (United States)? #
The locale option is resolved exactly, then by declared alias, then by dropping the region once; anything else throws POLYTYPO_UNKNOWN_LOCALE.
Declared alias: en → en-US.
| Tag | How it resolves |
|---|---|
en-US | registered locale |
en | declared alias |
en-AU | region removed, then a declared alias |
EN-us | registered locale, after case and separator normalisation |
en_US | registered locale, after case and separator normalisation |
Which quotation marks does English (United States) use? #
| Primary | “ U+201C left double quotation mark … ” U+201D right double quotation mark — no space inside the marks |
|---|---|
| Secondary | ‘ U+2018 left single quotation mark … ’ U+2019 right single quotation mark — no space inside the marks |
Elision idioms
When a narrow quote pair matches one of these exactly, the marks are not paired as a quotation.
| Before | Elided | After |
|---|---|---|
rock | n | roll |
Elision clitics
Word fragments that stand against an apostrophe at the edge of an inline span; a narrow mark next to one is not paired as a quotation.
| Before the apostrophe | none |
|---|---|
| After the apostrophe | s |
quotes
How are apostrophes set in English (United States)? #
apostrophe
Which dashes does English (United States) use for breaks and ranges? #
Parenthetical break (dash.parenthetical) | an em dash (U+2014) with no surrounding spaces |
|---|---|
Between numbers and dates (dash.range) | an en dash (U+2013) with no surrounding spaces |
The dashes rule reads the parenthetical convention. The ranges rule reads the range convention and is off by default.
dashes
ranges
The ranges rule is off by default; these cases enable it with rules: { ranges: true }.
options: rules: {"ranges": true}
options: rules: {"ranges": true}
options: rules: {"ranges": true}
How is the ellipsis set in English (United States)? #
An ellipsis keeps its full form after ! and ?; this locale does not abbreviate it there.
ellipsis
How are hyphens handled in English (United States)? #
The hyphen lists are empty for this locale, so the hyphen rule changes nothing.
Where does English (United States) use no-break spaces? #
Characters that take U+00A0 before them (nbsp.beforePunctuation) | none |
|---|---|
Characters that take U+202F before them (nbsp.narrowBeforePunctuation) | none |
Short words after which the space becomes U+00A0, so the word is not left at the end of a line (nbsp.afterShortWords) | none |
Multi-token abbreviations whose internal spaces become U+00A0 (nbsp.abbreviations) | none |
Units and signs bound to the preceding number with U+00A0 (nbsp.beforeUnits) | % kg g mg km m cm mm mi ft lb oz L mL h min s ms °C °F kB MB GB TB kW kWh |
Abbreviations bound to the following number with U+00A0 (nbsp.beforeNumber) | none |
Abbreviations bound to the following word with U+00A0 (nbsp.beforeWord) | none |
Symbols bound to the following number with U+00A0 (nbsp.afterSymbols) | none |
Initials (nbsp.initialBinding) | chain — a sequence of two or more adjacent initials is bound; a lone initial next to an ordinary capitalised word is left alone |
spaces
nbsp
How are symbols set in English (United States)? #
symbols
How does English (United States) text behave in text, HTML and Markdown modes? #
Each input is the locale's sample sentence followed by a code run, say("a -- b ..."). text mode sets the whole string as prose, code run included. In html and markdown mode the code run comes back byte for byte; only the prose is set.
How does English (United States) differ from English (United Kingdom)? #
en-US and en-GB are separate locales. Fields whose values differ:
| Field | en-US | en-GB |
|---|---|---|
quotes.primary.open | “ | ‘ |
quotes.primary.close | ” | ’ |
quotes.secondary.open | ‘ | “ |
quotes.secondary.close | ’ | ” |
quotes.elisionIdioms (entries only in one) | rock · n · roll | — |
dash.parenthetical | em-tight | en-spaced |
nbsp.initialBinding | chain | none |
The same input through both:
Which sources define English (United States) typography? #
11 citations in spec/locales/en-US.json, grouped by the rule each one supports. A citation names the authority; the note records what the source does and does not settle.
ellipsis
- The Chicago Manual of Style, 18th ed., ellipses (three dots) cmosshoptalk.com
`abbreviatedAfterTerminal` is false: the two-dot form after `!`/`?` is a Russian convention with no counterpart in English usage. Chicago’s spaced ellipsis (. . .) is a print-typesetting variant, not a separate character sequence this spec models.
dashes
- The Chicago Manual of Style — CMOS Shop Talk, “Hyphens and Dashes: A Refresher”, 23 January 2024 cmosshoptalk.com
Verbatim: “In Chicago style, such dashes consist of em dashes—like this—with no space before or after.” And: “When consecutive digits express a range, however, they are separated in Chicago style not by hyphens but by en dashes, as in the range 3–5.”
hyphen
- No English authority prescribes non-breaking hyphens for particular word forms; lists deliberately empty
`prefixes`, `suffixes` and `compounds` are empty. This field exists for languages with a closed, normative set of hyphenated morphological forms (Russian кое-, -таки, из-под). English hyphenation is productive and open-ended — self-, ex-, -like, well-known and thousands more — so any list would be an invented sample, not a specification. Chicago’s hyphenation guidance (its hyphenation table) governs whether to hyphenate, not whether the resulting hyphen may break, and Chicago explicitly permits breaking at a hyphen.
quotes
- The Chicago Manual of Style, 18th ed., 6.11 (quotations within quotations); CMOS Q&A, topic “Quotations” www.chicagomanualofstyle.org
US practice: double quotation marks at the first level, single at the second. CMOS 6.11: “When single quotation marks are nested within double quotation marks, and two of the marks appear next to each other, a space between the two marks, though not strictly required, aids legibility.” That optional legibility space is a typesetting refinement and is not expressed in this file.
- Chicago Manual of Style Online Q&A, topic “Special Characters”: “If you want, for example, an apostrophe rather than an opening single quotation mark at the beginning of a string (e.g., the apostrophe before the n in “rock ’n’ roll”), you must tell the computer that that's what you want.” www.chicagomanualofstyle.org
Supports quotes.elisionIdioms = [{ left: "rock", elided: "n", right: "roll" }]: the leading mark of the elision must not be resolved as an opening quotation mark. CMOS states the mark's function, not a code point; U+2019 follows from spec/rules/apostrophe.md, which is unchanged. Reproduced verbatim, including CMOS's own U+2019 in “rock ’n’ roll” — not straightened to U+0027 — because it is a direct quotation of the source's printed text. Edition/section not fully cited: the page reports 17th ed. in-body while the site titles itself 18th ed., and the numbered CMOS section is paywalled.
- American Heritage Dictionary of the English Language, entry “rock and roll”: headword line “rock-and-roll or rock 'n' roll”, the elided variant spaced as rock 'n' roll with a mark on each side of the bare word n. www.ahdictionary.com
Attests the spaced two-mark orthography of the "rock"/"n"/"roll" idiom only — this citation supports no other elisionIdioms entry. In particular it does not attest "fish 'n' chips", which is not listed here and would need its own citation before being added; the field is a closed set of individually evidenced idioms, not a general elision-word list.
- The Chicago Manual of Style, 7.16 “Possessive form of most nouns” (section number and title confirmed against the publisher's own chapter-7 table of contents; cited as 7.16–19 and 7.22 by the CMOS Q&A on the 18th-edition site). Verbatim, as reproduced by CMOS Shop Talk, “Section 7.16 in the Spotlight”, 12 May 2015: “The possessive of most singular nouns is formed by adding an apostrophe and an s.” Reconfirmed for the current edition by CMOS Shop Talk, 31 August 2021: “Chicago adds an apostrophe and an s to form the possessive of a singular noun, including singular nouns ending in s” (see CMOS 7.16) cmosshoptalk.com
Supports the single entry quotes.elisionClitics.after = ["s"] — the possessive s, not the contraction enclitics. t, ll, re, ve, d and m are deliberately absent: nobody writes `won`'t, so they have no attested occurrence in the shape this veto is scoped to, whereas possessivising a set-off identifier (`x`'s printer) is everyday technical prose and is the shape reported in canonical issue #53. Chicago states the rule, not a code point; U+2019 follows from apostrophe.md §3.3, which is unchanged. Edition and section provenance is mixed deliberately and should not be tidied into a single number: the numbered paragraph itself is paywalled, the verbatim wording above is the 16th edition's (the 2015 post carries an editor's note saying so), and the 2021 post plus the 18th-edition Q&A are what establish that 7.16 is still the general rule. CMOS 7.22's alternative practice (Burns' rather than Burns's) does not affect this entry: the veto matches the maximal LETTER run to the RIGHT of the mark, so Burns's fires on s while Burns' has no letter there and fires nothing. CMOS 7.29 “Possessive with italicized or quoted terms” is a closer fit to the reported shape than 7.16 and would strengthen this citation, but its text is paywalled and was not read — only its title, from the table of contents.
nbsp
- The Chicago Manual of Style — CMOS Shop Talk, “Navigating Spaces in Manuscripts and Beyond”, 15 June 2021 cmosshoptalk.com
Chicago recommends a nonbreaking space “between two or more initials in a name like ‘E. B. White’” (hence initialBinding: "chain" — spec 0.6.0: the field used to be the boolean bindInitials; Chicago's own “two or more” wording is the citation for the chain requirement, not merely for turning N7 on) and “between a numeral and an abbreviated unit of measure, as in ‘10 kg’” (hence beforeUnits).
- BIPM, The International System of Units (SI), 9th ed. (2019), concise summary, “The language of science: using the SI to express the values of quantities” www.bipm.org
Verbatim: “A single space is always left between the number and the unit.” This is the authority for the unit list itself; Chicago is the authority for making that space non-breaking. `%` is included even though Chicago sets percentages closed up (45%): the rule only converts a space the author already typed, and a spaced `45 %` in English is a deliberate scientific-style choice worth binding.
- No normative source found for English short-word binding; list deliberately empty
`afterShortWords`, `beforePunctuation` and `narrowBeforePunctuation` are empty by design. English typography has no equivalent of the Russian rule against leaving short prepositions at line end, and no English authority prescribes a space before terminal punctuation. `afterSymbols` is empty because no consulted source states that `§`/`№` bind to a following number in English.
- The Chicago Manual of Style Online, Q&A, topic “Word Division”: “we don’t include any recommendation that says you must carry an abbreviation that ends in a period over to the next line when the sentence continues beyond the abbreviation. So a line is allowed to end with an ‘a.m.’ or ‘Jr.’ or the like that occurs in the middle of a sentence.” www.chicagomanualofstyle.org
`beforeNumber` and `beforeWord` are empty, and Chicago does not merely omit reference abbreviations from its nonbreaking-space guidance — it states positively that no such rule exists, so `No. 5`, `p. 12` and `pp. 12–14` are refused on the source’s own words rather than on an argument from silence (issue #30). The same answer attributes the practice to typesetters rather than to Chicago: “some typesetters will use a nonbreaking space to prevent a compound like ‘St. Louis’ or ‘Dr. Smith’ from breaking at the end of a line” — which is why `beforeWord` stays empty too; the named exception is initials in a name, carried by `initialBinding`. CMOS Shop Talk, “Navigating Spaces in Manuscripts and Beyond” (15 June 2021), cited above for `initialBinding` and `beforeUnits`, introduces its four contexts with “can be helpful in the following contexts, among others”, so it must not be described as an exhaustive list.