Comma the purpose of the comma. There are also a number of comma-like diacritics with "COMMA" in their Unicode names. These do not serve a punctuation function. A comma-like low quotation mark is also available (shown below; raised single quotation marks are not shown). Various other Unicode characters combine commas or comma-like figures with other characters, and are not shown here. In the 3rd century BC, Aristophanes of Byzantium invented a system of single dots ("distinctiones") that separated verses (colometry) and indicated the amount of breath needed to complete each fragment of the text when reading aloud. The different lengths were
Punctuation of English their cover letters. In contrast, closed punctuation uses commas and periods in a strict manner. Closed style is common in presentations, especially in bulleted and numbered lists. It is also frequently used in advertising, marketing materials, news headlines, and signage. The approximate average frequencies for English punctuation marks per 1000 words based on 723,000 words of assorted texts are as follows (as of 2013, but with some text corpora dating to 1998 and 1987): The apostrophe , (sometimes called inverted comma in British English) is used to mark possession as in ""John's book"", and to mark letters omitted in contractions,