Ignatius insisted that Jesuits speak the language of the country where they reside, and he saw this as an indispensable means of promoting unity in the community. At the beginning of each year this instruction was renewed and sent to all superiors, and eventually was incorporated into the Common Rules (#10). To help the non-Italian Jesuits in Rome, Ignatius arranged for Italian classes three times a week, but then in 1555 he changed it to daily classes. This instruction exists in an Italian version [Ep. 10:451-452].
Jhus
The Peace of Christ.
It seems fitting for the benefit and edification of the peoples among whom our Society is living, and for the increase of union, charity, and good will among Ours, that in places where we have a college or a house all who do not know the language which is in common use should learn it and as a rule speak it. If each one were to speak his mother tongue, there would be much confusion and lack of union, seeing that we are of different nations.
For this reason our Father has given orders that in all places where the Society exists, all of Ours should speak the language of that country. In Spain, Spanish; in France, French; in Germany, German; in Italy, Italian; and so on. He has given orders that here in Rome all should speak Italian, and every day there are lessons in Italian grammar to help those learn it who are unable to use it. No one is allowed to speak to another except in Italian, unless it be to make clear the meaning of some words and thus be better understood. Once a week in the refectory, either at dinner or supper, there is an Italian sermon in addition to the tones which is regularly held. Care is taken that some of those who are skilled in Italian help the others, so that they can compose their sermons with greater ease. A good penance is given to those who fail in their observance of this regulation.
Likewise our Father has given orders that this same rule be written out and kept everywhere in the Society as carefully as possible, due consideration being had for differences of places and persons. For this reason we are writing to your reverence to see that the regulation is observed. Please advise us when you receive this.
May Jesus Christ be with us all.
From Rome, January 1, 1556.