In chapter 15, Rochester explains to Jane how her French pupil Adèle came to be at Thornfield Hall: ‘she was the daughter of a French opera dancer, Céline Varens; towards whom he had once cherished what he called a “grande passion.” This passion Céline had professed to return with even superior ardour.’
Rochester uses a French phrase, though one that is readily comprehensible in English, to veil his affair and distance himself from it, introducing a note of melodrama and exoticism. If you call something a ‘grande passion’ you may well mean to suggest that it is not so deep-rooted as a ‘great passion’ would have been (‘“une grande passion” is “une grande folie”, as Brontë wrote in a letter to her friend Ellen Nussey.) 
In the next sentence, Jane, narrating, translates the French ‘passion’ into English ‘passion’ as Rochester’s passion is reflected by Céline. In this English translation the question of honesty is made explicit: his ‘“grande passion”’ (a French phrase used by an Englishman) may be hot-headed, but her ‘passion’ (now an English word used of a French woman) is only ‘professed’. Translation within the text becomes a means of ethical appraisal.
The translators often recreate the switch from French ‘passion’ to an equivalent in their language, though the spelling is never identical as it is with the French / English word. Sometimes, a language’s liberty with pronouns enables a translator to put the two terms exactly side by side (Hill, Sp2009: ‘… passion. Pasiòn …’; Pareschi, It2014: ‘… passion. Passione …’.
And there are many other ways of translating this little scene of translation. Sometimes ‘passion’ is glossed, creating a bridge towards the description of Céline’s response (as with Stanevich, R1950); sometimes she is allowed the French word too (Rohde, D2016R); sometimes the connection is made by a switch from verb to noun (Ferreira, Por1951); sometimes the translational jump from Rochester’s ‘passion’ to her equivalent is abandoned, and her professed feeling is described in different terms; and sometimes the same word, in the language of the translation, is used for both Rochester’s and Céline’s actual or apparent feelings, as in Ben Dov’s use of ‘תשוקה [teshuka]’, He1946 (followed by Bar, He1986). As Adriana X. Jacobs comments: ‘In Hebrew, “teshuka” is related to the root sh.u.k., to run after, often used in the sense of longing and physical desire (in Rabbinic literature, the desire of a wife for her husband)’.
In each case, the translators are re-creating in their own language the sparks (including a spark of irony) that jump between the two kinds – two languages – of passion that Brontë imagined and wrote down. They are answering Brontë’s text more intimately than Celine has answered to Rochester. Here you can trace their re-imaginings across four screens of variants:
Next: judgment and passion.
Text and animation by Matthew Reynolds, incorporating research by Eugenia Kelbert, Céline Sabiron, Ana Teresa Marques dos Santos, Andrés Claro, Adriana X. Jacobs, Matthew Reynolds, Yousif M. Qasmiyeh, Jernej Habjan, Ida Klitgård, Kayvan Tahmasebian, Ulrich Timme Kragh.
 The Letters of Charlotte Brontë, 2 vols, ed. Margaret Smith (Oxford, Clarendon Press, 1995-2000), i, p. 233. Online: Intelex Past Masters Full Text Humanities.