Thanks.  This clears up the matter entirely.

Bottom line, you can use either word.

You can, but I definitely think the "inferos" without the n is preferred, since it's the version used by the Council of Trent even ... so that's what I use when I pray (I pray the Rosary in Latin typically), but it would not be some kind of "error" to use "infernos", as long as it's clear that "infernos" doesn't mean Hell of the damned, becaue the English derivative can more strongly suggest that than the original "inferos".

With regard to the Catechism of Trent referring to those in Limbo of the Fathers suffering by longing, whoever wrote those passages appeared to be holding to the St. Augustine opinion that even those in Limbo suffer at least a pain of loss.  Now, St. Augustine later softened his position by holding that this suffering was extremely mild, but (and we'd watn to see the Latin), the translation above seems to be the stronger opinion that they are "tortured" in "Paradise".  I just don't believe that St. Joseph, St. John the Baptist, et al. were being "tortured" or, really, suffering at all ... for the same reasons St. Thomas gave that the infants in Limbo Infantium do not suffer.

Here's a case where people shouldn't be scandalized by disagreeing with some of the more speculative expository sections of the Roman Catechism (there are actually some significant doctrinal slips in there even), since it wasn't infallible in every word of its 600-700 pages as if each sentence had been a solemn dogmatic definition.  Unfortunately, the tug of dogmatic SVism has pulled Traditional Catholics in that direction, and I've even had R&R priests (one now Resistance or "True Resistance") who was scandalized (aka shocked) when I told him I disagree with a certain opinion held by St. Thomas Aquinas.

"This day you shall be with Me in Paradise." said Jesus to the good thief on Friday.

Good point.  I'd never thought of it that way.