In the original English Harry Potter, spells are cast by uttering the spell and waving one's wand. The spells are largely in Latin or mock Latin. The three CJV languages differ broadly in their treatment.

Both the Chinese and Taiwanese translators try most of the time to translate spells into Chinese. The Mainland translator has a preference for four-character expressions. The Taiwanese translator goes for three-character expressions, sometimes preceded by a suitable sound.

The Japanese translator generally transliterates the Latin spell into katakana. After the katakana she gives the meaning in Japanese. This is quite acceptable to the Japanese, who not only uncomplainingly accept large numbers of katakana expressions from English, but actually prefer such expressions for the 'sophistication' and 'authenticity' they bring. The downside is that katakana is a rather poor tool for representing mock Latin, which is not helped by inconsistencies in the transliteration.

The Vietnamese translator uses the English spell unchanged in Books 1-4, with footnotes where necessary to explain the meaning. In Book 5, however, she changes tack to use Vietnamese only to translate spells. Through all this, there is remarkable inconsistency from one occurrence to the next. (Thanks to this inconsistency, I may have missed some of the Vietnamese versions of each spell In the table below).

For a comparison of Mainland and Taiwanese versions, see this paper: Spell Translation in Harry Potter From the Perspective of Skopostheorie: A Comparative Analysis on the Versions From Mainland China and Taiwan.