In "The Guest," there are two reasons why the conversations between Daru and the Arab prisoner are difficult. First of all, there is a language barrier between the two men. Daru speaks French, for example, but the Arab does not, as Balducci makes clear early on. Fortunately, Daru speaks Arabic, the language of the prisoner, but he is not a native speaker and may not be fully proficient.
Secondly, there are considerable cultural differences between the two men because of their different backgrounds. Daru, for instance, was born in Algeria but is a French citizen who works in a school. In contrast, the Arab is a local villager who has no cultural affiliation to France but is subject to her imperial authority. We see evidence of this cultural difference when the two men discuss the Arab's crime. The Arab, for example, is shocked by Daru's openness when he asks if the Arab feels remorse:
"The Arab stared at him openmouthed. Obviously he did not understand."