Sindarin 

pen

cardinal. one

(indefinite pronoun) (= somebody, anybody) pen (WJ:376); lenited ben. According to one interpretation of the phrase caro den i innas lín from the Sindarin Lords Prayer (VT44:23), this could mean *”let one do your will”, with den (perhaps a lenited form of *ten) as the indefinite pronoun ”one”. However, others interpret den as the accusative form of the pronoun ”it”: ”Do it [, that is:] your will”.