FUNCTION

The apostrophe (or “single quote” for English speakers) is a very common punctuation mark in languages using the Latin alphabet. It has different functions from one language to another. In English, for example, it is used as a possession (“part of a letter” to “a letter’s part”) or an elision marker (“it is” to “it’s”).

HISTORY

A symbol looking like an apostrophe dates back to the 16th century in France when the engraver Geoffroy Tory (1480–1533) introduced this sign to replace a letter or a short word.
With the invention of typewriters, other look-alike glyphs (single quote, prime, acute accent, etc.) were assembled into the same key with the apostrophe to save as many keys as possible for the limited space of the keyboard. But this led to confusion that is still observed nowadays, with the prime glyph being often used as an apostrophe.

DESIGN

Well-designed typefaces either have slanted or curly-shaped apostrophes (related to the comma of the typeface). This shape avoids confusion with the prime.