Hook Above (Dấu Hỏi)
History and examples of use
The hook above, or dấu hỏi, is a diacritic mark placed on top of vowels in the Vietnamese alphabet. It resembles a tiny question mark without the dot underneath. For example, a capital A with a hook is "Ả", and a lower case "u" with a hook is "ủ". It functions as a tone marker. Vowels with this symbol are pronounced with a falling then rising tone.
Design
The hook above should not be derived from a question mark, since the latter is too large. (It should be emphasized that the dot at the bottom of a question mark is always inappropriate in this diacritic). The bottom stem should be curved or truncated; it should not resemble the glottal stop symbol (U+0294). The hook is often used with other diacritics, such as a breve above A, or a circumflex above A, E or O. The hook should always be placed above a caron or a circumflex, if present.