information:classification, structural:reformatting, information:filtering, information:extraction
しんいち The apostrophe is a punctuation mark, and sometimes a diacritical mark, in languages that use the Latin alphabet and some other alphabets. In English, the apostrophe is used for three basic purposes:
  - The marking of the omission of one or more letters, e.g. the contraction of "do not" to "don't"
  - The marking of possessive case of nouns
  - Use as a single quotation mark It is also used in a few distinctive cases for the marking of plurals, e.g. "p's and q's" or Oakland A's. It is also used informally to indicate the units of foot and minutes of arc, although in these uses, the prime symbol is generally preferred. The word apostrophe comes from the Greek ἡ ἀπόστροφος [προσῳδία], through Latin and French.