This is about standard usage of spaces before/after colons and the like,
not about fonts. Unless specified otherwise, the following typography
rules apply to French, English and German.
Two examples:
En français: Einstein a (peut-être) dit :
« J'adore 3,14, 298 000 — et
42 ! ».
In English: Einstein said: "3.14,
298,000—and 42—are my all-time favourite numbers!" (or maybe he
didn't.)
Comma, full stop, ellipsis: , . ...
No space before, one space after. English usage may use two spaces
after a full stop or an ellipsis.
Colon, semicolon, question mark, exclamation mark: : ; ? !
French: one nonbreaking space before, one space after. The rule is
that
there are as many spaces as there are elements in the punctuation
mark. For
example, a colon is surrounded by two spaces because it contains two
elements (two dots); a comma contains only one element, therefore it is
surrounded by
one space (after).
English, German: no space before, one or two spaces after. Two
spaces may be necessary with monospaced fonts, but only one space
is used in standard typography.
In my opininion, the French rule is a little more readable, but it
is often inconvenient with computers because because not every software
handle nonbreaking spaces properly.
Apostrophe, hyphen, slash: ' - /
Use the no-space-before/no-space-after rule. Use the same rules for the
various kinds of quotation marks used in English.
En dash, Em dash: – —
This is about en dashes and em dashes—as opposed to (shorter)
hyphens (-). In French, use one space before and one space after. In
English, people usually don't put spaces around dashes.
Parentheses, square brackets, double quotes: ( ) [ ] "
One space in the outside, no space in the inside. Note that the English
double quotes (") are not used in French (in theory). Also note that,
while the American "put the continuation commas and the final period
inside the string quotes," the French (and apparently the British) "put
them outside".
Guillemets: « » (French quotation mark)
One space before and after the « guillemet ». The
space after the opening
quote and the space before the closing quote should be nonbreaking.
French accents
I am speaking about acute and grave accents, as in é or
è, not about the strange noise French people produce when they
try to speak English.
People tend to avoid using accents in capital letters (Á,
À, É,...) because they are difficult to type, even on a
French keyboard, but it is recommended to use them to remove some
ambiguities.
Also note the following rule: if a punctuation mark follows another
punctuation mark, the rule associated with the second one prevail over the
rule associated with the first one. For example, a closing parenthese will
be followed by no space if the next character is a full stop.
Word division
Sometimes you need to divide a word between two lines.
French: cut the word between two syllables. Don't do it if one of
the resulting parts would contain only one letter. Examples:
atmos-phère, ordi-naire, ap-prouver.
English: divide the word according to its formation, or between a
vowel and a consounant, or between double letters. Example:
atmo-sphere, ordi-nary, ap-prove.
Notice the difference between French and English in the first example of each series.
Numbers
Numbers are usually written with letters from one to ten, and
with digits above 10.
French: one (nonbreaking) space is inserted every third character
starting at 10 000. And a comma is inserted between the integral part
and the decimal part of a number. No space after this comma.
English, German: a comma is inserted every three character
starting at 10,000. And a dot is inserted between the integral part
and the decimal part of a number. No space after the comma or the dot.
However, scientific publications in English generally use spaces, i.e
10 000 not 10,000, except Nature which still uses 10,000.
Do not accept a job payed 150,000 francs/month if
the employer is
French!
Centuries
The French live in the XXIe siècle, while the English
live in the 21st century and the German in
21. Jahrhundert.
Dialogues
In French, every retort in a dialogue is introduced with a (long)
dash (). Sometimes the entire dialogue is enclosed between
guillemets, but this is not mandatory:
« Il faut avouer, monsieur Ralph, reprit-il, que vous
avez trouvé là une manière plaisante de dire que la terre a diminué ! Ainsi
parce qu'on en fait maintenant le tour en trois mois...
En quatre-vingts jours seulement, dit Phileas Fogg.
En effet, messieurs, ajouta John Sullivan, quatre-vingts
jours.»
(Jules Verne, Tour du monde en quatre-vingt
jours)
In English, double quotes (") are used:
"Try one of these," said the Admiral, holding out his
cigar-case. (Conan Doyle, Beyond the City)
While double quotes are widely used in handwritten texts, most books, except in America, use single quotes.
Although I have checked every information, there are
probably a few errors in this node. Please /msg me if you find them.
Gritchka provided some additional information. Thanks!
A few references:
http://nte.univ-lyon2.fr/~poitou/Enseignements/Typo.html
http://www.interpc.fr/mapage/billaud/ponctua.htm
http://www.bartleby.com/141/strunk.html#8
http://www.fontsite.com/Pages/RulesOfType/ROT0997.html
The Jargon File