A rather complicated story: Arendt wrote a review of a German book that—in the middle of the war—was available to her only in English translation. She wrote her review in German, and an unknown translator rendered the text in English. In her original version, Arendt at times translated passages from the book back into German herself; in these cases, we have decided to present both the English she was using as well as the actual German original in the annotations to her German version. In all other cases, the English quotations are to be found in the English apparatus, with references to the German original.
See the more detailed German editorial commentary here.