Can we say Brothers or Sisters at the I confess at Mass when those present are all males or all females

Can we say “Brothers” or “Sisters” at the “I confess” at Mass when those present are all males or all females?

The use of brothers and sisters at the Confiteor at Mass is a particularity of the English language. In many languages, the masculine form does a double duty and can refer to just males or to a mixed group of men and women. Thus, for example, in Latin, Spanish and Italian it is only necessary to use the equivalent of “brothers” to refer to the whole assembly (in the recent revision of the Italian Missal of 2020, “sorelle”, i.e. “sisters”, has been introduced).

In English “brethren” can serve this purpose and in fact may be used to introduce the penitential rite. However, perhaps for stylistic reasons, it was not included as part of the “I confess.” Thus in the English translation we say “brothers and sisters.”

All the same, some contextual adaptation is foreseen in the rubrics. For instance, when Mass is celebrated with only one acolyte, the rubrics state that the priest and acolyte say “to you my brother” in the singular. Therefore, it is theoretically possible for a male community to use simply “brothers” when no women are present. This is also possible when priests have gathered together to celebrate the Eucharist, for example, at a retreat for priests.

Notwithstanding, a little caution here is to remember that since liturgical expressions are habit-forming, if, on some occasion, there are women from outside the community present at the celebration, then the change could easily lead to some confusion. Thus, it is pastorally recommended, as a general  rule, to keep the standard formula of the “I confess”.

The case is however different for a female community because at Mass at least one brother will always be present (the celebrating priest). Therefore, here, the standard formula should be used.

Read more:

https://www.ewtn.com/catholicism/library/brothers-or-sisters-4610