German to Italian: an indirect relative needs its relation, not a copied German ending
Case in the German phrase identifies a source role
German marks case on pronouns and noun-related words, and permits objects governed by verbs or prepositions in several cases. In a German relative description, these forms help identify whether a person acts, is addressed, or stands in another relationship to the action. Italian cui is invariant, as the Accademia della Crusca explains. Its unchanged spelling does not mean those source relationships have disappeared.
For a German phrase meaning “the colleague with whom I spoke,” the important connection is companionship in the speaking event. In an Italian indirect relative, the appropriate preposition supplies that relation with cui. A target form should therefore not be judged deficient merely because it lacks a gender or case ending resembling the German relative form.
An owner inside a relative description is not the person performing every action
Compare the meanings “the colleague whose report I read” and “the colleague to whom I read the report.” The first connects the report to its owner or author; the second makes the colleague a recipient of reading. A translation preserving only the words colleague and report could still reverse their grammatical relationship.
Crusca explains the possessive construction in which cui appears between an article and a noun, without an additional di. This differs from choosing a preposition before an ordinary indirect relative. A German possessive relative therefore should not mechanically receive the same Italian pattern as every source phrase containing a case-marked relative pronoun. The entire article-plus-cui-plus-noun group expresses the ownership connection.
Invariant cui does not make the surrounding phrase invariant
Crusca’s example le cui azioni demonstrates that the larger phrase can contain an article and noun with their own agreement even though cui itself remains unchanged. A German description of one person’s several actions must retain the plurality of those actions. The absence of a plural ending on cui is not a reason to make the following noun singular.
The same consultation distinguishes a dative use where a before cui can be omitted from uses where a preposition is required. This is a specific constructional option, not permission to remove relation words freely. In a German message referring to a person from whom a report was received, the origin relationship differs from the recipient relationship in sending it to that person. Omitting or replacing the target preposition can therefore change the correspondence being described. Identify the antecedent, the role it occupies inside the description, and any separately possessed noun before evaluating the Italian relative. German case morphology provides evidence about that source structure; Italian conveys it through the selected relative construction, preposition, article, and following noun. A single unchanged cui can participate in several patterns without making those patterns interchangeable.
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