S. caro den i innas lin “thy will be done”
The fourth line of Ae Adar Nín, Tolkien’s Sindarin translation of the Lord’s Prayer (VT44/21). The first word caro is the imperative form of the verb car- “to do”. The third word is the definite article i¹ “the”, followed by innas “will” and the possessive pronoun lin “your”, with the adjectival element following the noun as is usual in Sindarin.
The function of the word den in this phrase is unclear. Bill Welden suggested (VT44/25) that is a marker of the passive voice (“thy will be done” instead of “do thy will”), and is the lenited form of ten, either a 3rd-plural pronoun “they” (as in impersonal English phrases such as “they say ...”) or a neutral pronoun “it”. Since “they” appears as di (← ti) elsewhere in the prayer, I think the second possibility is more likely.
Decomposition: Broken into its constituent elements, this phrase would be:
car-o den i innas lin = “*do-(imperative) it the will yours”
Reference ✧ VT44/21 ✧ “thy will be done”
|car-||“to do, make”||imperative||✧ VT44/25 (caro)|
|#ten||“*it, passive voice marker”||soft-mutation||✧ VT44/25 (den)|
|lín||“*thy”||✧ VT44/24 (lin)|