<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The comma (,) is a punctuation mark that appears in several variants in various languages . It has the same shape as an apostrophe, or single closing quotation mark in many typefaces, but it differs from them in being placed on the baseline of the text . Some typefaces render it as a small line, slightly curved or straight but inclined from the vertical, or with the appearance of a small, filled - in numeral 9 . </P> <P> The comma is used in many contexts and languages, mainly for separating parts of a sentence such as clauses, and items in lists, particularly when there are three or more items listed . The word comma comes from the Greek κόμμα (kómma), which originally meant a cut - off piece; specifically, in grammar, a short clause . </P> <P> A comma - shaped mark is used as a diacritic in several writing systems, and is considered distinct from the cedilla . The rough and smooth breathings (ἁ, ἀ) appear above the letter in Ancient Greek, and the comma diacritic appears below the letter in Latvian, Romanian, and Livonian . </P>

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