相信对于 o'clock 这个用法大家都不陌生
An apostropheis used in o'clock because the word is a contraction of the phrase "of the clock." Just like other contractions, the apostrophe takes the place of missing words or letters from a longer word or phrase. For example, the apostrophe in "don t" takes the place of o in the word "not," and the apostrophe in "you'll" takes the place of wi in the word "will."
o'clock中撇号的使用，是因为这个词是"of the clock"这个短语的缩写。就像其他的缩写一样，撇号可以代替长单词或短语中漏掉的单词或字母。例如，don t中的撇号代替not中的o，而you'll中的撇号代替will中的wi。
When we use the word o'clock we are saying that it is a particular hour "according to the clock." For example, "it is almost four o'clock" means the same as "it is almost four according to the clock." However, the full phrase "of the clock" is not used by native English speakers. Always use the shortened form, "o'clock."
当我们使用“o'clock”这个词时，我们是在说它是根据时钟这个计量时间的仪器而来的时间。例如，it s almost four o'clock(差不多4点)和it s almost four according to the clock(根据时钟)的意思是一样的。以英语为母语的人一般不用"of the clock"的完整形式，而会使用缩写形式o'clock。
Using the form of “o'clock” particularly increased in popularity around the eighteenth century when it became common to do a similar slurring in the names of many things such as “Will-o -the wisp” from “Will of the wisp” (stemming from a legend of an evil blacksmith named Will Smith, with “wisp” meaning “torch”) and “Jack-o -lantern” from “Jack of the lantern” (which originally just meant “man of the lantern” with “Jack,” at the time, being the generic “any man” name.
Later, either this or the Irish legend of “Stingy Jack” got this name transferred to referring to carved pumpkins with lit candles inside).
这种把of缩写成o 的习惯大约在十八世纪特别流行，那时候人们开始把很多名字发成类似的含糊的音——比如说“Will of the wisp（鬼火）”变成“Will-o -the wisp”(源自一个名叫威尔·史密斯的邪恶铁匠的传说，而wisp的意思是火炬)和“Jack of the lantern（杰克南瓜灯）”变成“Jack-o -lantern”(在当时，它的意思是“拿着灯笼”的“杰克”，是“任何男人”的通称。后来，不论是这个短语还是爱尔兰传说中吝啬的杰克的故事都变成了里面有点燃蜡烛的雕刻有恶魔脸南瓜灯的意思）。
While today with clocks being ubiquitous and few people, if anybody, telling direct time by the Sun, it isn’t necessary in most cases to specify we are referencing time from clocks, but the practice of saying “o’clock” has stuck around anyway.