According to Derrida, the first violence to foreigners is requiring them to understand a foreign language. While this may be obvious in mundane cases, Derrida's point is more general.
Derrida mentions the case of Socrates at his trial, disadvantaged by not knowing the language of law:
Quote
He declares that he is "foreign" to the language of the courts, to the tribune of the tribunals: he doesn't know how to speak this courtroom language, this legal rhetoric of accusation, defense, and pleading; he doesn't have the skill, he is like a foreigner.
...
[The Foreigner] has to ask for hospitality in a language which by definition is not his own, the one imposed on him by the master of the house, the host, the king, the lord, the authorities, the nation, the State, the father, etc. This personage imposes on him translation into their own language, and that's the first act of violence.
- Of Hospitality pdf 
.