<Dd> Punctuation apostrophe . Serves as both an apostrophe and closing single quotation mark . This is the preferred character to use for apostrophe according to the Unicode standard . </Dd> <Ul> <Li> U + 02BC ʼ MODIFIER LETTER APOSTROPHE </Li> </Ul> <Li> U + 02BC ʼ MODIFIER LETTER APOSTROPHE </Li> <Dl> <Dd> Modifier letters in Unicode generally are considered part of a word, this is preferred when the apostrophe is considered as a letter in its own right, rather than punctuation that separates letters . Thus this letter apostrophe may be used, for example, in the transliteration of the Arabic glottal stop (hamza) or the Cyrillic "soft sign", or in some orthographies such as cʼh of Breton, where this combination is an independent trigraph . Some consider, though, that this character should be used for the apostrophe in English instead of U + 0027 or U + 2019 . Also ICANN considers U + 02BC as a proper character for Ukrainian apostrophe within IDNs . This character is rendered identically to U + 2019 in the Unicode code charts . As the distinction between the letter apostrophe and the punctuation apostrophe may not be used in practice, the Unicode standard cautions that one should never assume text is coded thus . </Dd> </Dl>

When do you use the 's or s'