An en dash is the equivalent of the Japanese ~, used when indicating periods/lengths of time, book pages, and other numbers.
July 9–August 17; pp. 37–59.
"The en dash is slightly longer than the hyphen but not as long as the em dash. (A common myth holds that the en dash is, in fact, the width of a typesetter’s letter “N,” whereas the em dash is the width of the letter “M”—thus their names. In fact, an em is a typographical unit of measurement.)
The en dash means, quite simply, “through.” We use it most commonly to indicate inclusive dates and numbers: July 9–August 17; pp. 37–59.
Many people were not even aware of the distinction between the en dash and the em dash until the advent of word processors, when software programs enabled us to use marks of punctuation that once had been available only to professional printers."
On both PCs and Macs, two hyphens (typed with no space before or after either of them) will convert to an em dash—the full-length one that most of us think of when we hear the word “dash.”
Yes, and em dash is that "long dash". A hyphen is, to my eyes, the same as the "minus sign" in mathematics.
When I was learning typography--many years ago--the convention was that you did NOT use spaces around en- or em-dashes. If the type designer wants extra space for readability or aesthetics, they will build it into the slug for the type (or in more modern cases, program it into the font).
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Just FYI : En dashes are also used to connect a prefix to a proper open compound: for example, pre–World War II. In that example, “pre” is connected to the open compound “World War II” and therefore has to do a little extra work (to bridge the space between the two words it modifies—space that cannot be besmirched by hyphens because “World War II” is a proper noun). Now, that is a rather fussy use of the en dash that many people ignore, preferring the hyphen.
Extra uses:
Em dashes also substitute for something missing. For example, in a bibliographic list, rather than repeating the same author over and over again, three consecutive em dashes (also known as a 3-em dash) stand in for the author’s name. In interrupted speech, one or two em dashes may be used: “I wasn’t trying to imply——” “Then just what were you trying to do?” Also, the em dash may serve as a sort of bullet point, as in this to-do list:
Acronym is a fairly recent word, dating from the 1940s, although acronyms existed long before we gave them that name. The term was preceded in English by the word initialism, meaning an abbreviation formed from the initial letters of a phrase, and which has been in use since the late 19th century.
Some people feel strongly that acronym should only be used for terms like NATO, which is pronounced as a single word, and that initialism should be used if the individual letters are all pronounced distinctly, as with FBI. Our research shows that acronym is commonly used to refer to both types of abbreviations.
initialism is 頭文字語 かしらもじご
acronym is 頭字語◆ とうじご 例えば、North Atlantic Treaty Organization=NATO(ネイトー)のように、頭文字を並べたものが一つの単語として発音可能なもの。◆【参考】initialism
... but, in Japanese, acronyms can also be called 頭文字語 かしらもじご
A Japanese blog entry about all of this, although I haven't read it to verify it it's accurate. http://rhymosphere.cocolog-nifty.com/blog/2008/08/post-bb09.html