Italian Cui: All Functions (Di Cui, A Cui, Per Cui) (B1)

🔍 In short. The Italian word cui does one job and does it everywhere: it stands in for a noun inside a relative clause, always paired with a preposition. Italian cui functions split neatly by which preposition is glued in front: a cui for indirect objects (the person you spoke to), di cui for verbs that take di (the book you talked about), in cui for place and time (the year you were born), con cui for company, da cui for origin, su cui for surface or topic, per cui for reason or as a sentence-level “and so”, and the possessive il cui / la cui / i cui / le cui for “whose”. This guide walks you through each one with a couple at the Spoleto Festival dei Due Mondi, Sveva and Ottavio, who use the whole set in a single afternoon.

The reason Italian needs cui at all is simple: Italian refuses to leave prepositions hanging at the end of a clause. English happily says the friend I went with; Italian must say l’amico con cui sono andato, with the preposition welded to the relative. Once you internalise that one rule, the seven or eight Italian cui functions stop looking like a list to memorise and start looking like one pattern repeated. Each of the Italian cui functions then becomes a matter of picking the right preposition.

By the end of this guide on the Italian cui functions you will know when cui can drop its preposition (only one of the Italian cui functions allows the drop), why il cui libro uses il even when the owner is a woman, why per cui often acts like a sentence connector, and when natives quietly switch from the Italian cui functions to il quale instead. Then you can take the quiz and lock the whole set in.

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Why Italian needs cui at all

Picture Sveva at the Festival dei Due Mondi in Spoleto, looking for the seat next to the friend she came with. To understand the Italian cui functions, start from this everyday scene. In English she would say I’m looking for the friend I came with, dropping the preposition with at the end. In Italian that sentence is impossible. The preposition must stay attached to its noun phrase, and the relative pronoun that links the two clauses must carry the preposition on its back. That carrier is cui: cerco l’amica con cui sono venuta. Without cui, the sentence would either strand con at the end (ungrammatical) or use che after a preposition (also ungrammatical). Cui is the only pronoun that can sit between a preposition and the rest of the relative clause.

The mechanics of all the Italian cui functions reduce to one single move. Pick the verb or expression that governs your noun (parlare di, telefonare a, abitare in, viaggiare con, partire da, contare su, votare per). The preposition that verb wants goes in front of cui. The result is one of the eight Italian cui functions: di cui, a cui, in cui, con cui, da cui, su cui, per cui, tra cui. The pronoun itself never changes shape: cui stays cui, whether the noun it replaces is masculine, feminine, singular or plural.

The one exception to “always with a preposition” is the silent a. When the missing preposition would be a in its indirect-object role (the person you wrote to, telephoned, gave something to), modern Italian allows you to drop it. La persona a cui ho scritto and la persona cui ho scritto are both correct. This is a Latin survival from the indirect-object case, and Treccani lists it as fully acceptable. With every other preposition the drop is impossible.

A cui: the indirect-object slot

The first of the Italian cui functions covers what schoolbooks call the indirect object: the person or thing you write to, telephone, hand something to, ask a question of. Of all the Italian cui functions, this one is the most frequent in everyday speech. The Italian verbs that govern this slot all take a: scrivere a, telefonare a, dare a, chiedere a, rispondere a, dire a, raccontare a, regalare a, prestare a, mandare a, parlare a. When you wrap a relative clause around one of those verbs, you get a cui.

• Il maestro a cui Ottavio ha chiesto un autografo era gentilissimo.
  The conductor Ottavio asked for an autograph was very kind.
• La signora a cui ho prestato il programma siede in seconda fila.
  The lady I lent the programme to is sitting in the second row.
• Gli amici a cui Sveva ha telefonato non sono ancora arrivati.
  The friends Sveva called haven’t arrived yet.
• Non ricordo l’agenzia cui ho mandato la mail per i biglietti.
  I don’t remember the agency I sent the email to for the tickets.

The last example uses bare cui without a. This is the Latin indirect-object survival mentioned above: Treccani notes that with verbs of giving, writing, telephoning, both a cui ho scritto and cui ho scritto are correct. In conversation Italians keep the a more often, because it makes the sentence more transparent. In careful writing the bare form returns, and it sounds slightly more polished. With every other preposition (di, in, con, da, su, per, tra) the drop is not an option, and the bare-cui shortcut stays unique among the Italian cui functions.

Di cui: verbs that take di

The second of the Italian cui functions hangs off verbs and expressions that govern di. Of the Italian cui functions, this group has by far the longest list of triggering verbs: parlare di, scrivere di, discutere di, occuparsi di, fidarsi di, ricordarsi di, accorgersi di, aver bisogno di, aver paura di, aver voglia di, dubitare di, lamentarsi di, pentirsi di, vergognarsi di, andare orgoglioso di. Whenever the verb in the relative clause is one of these, the relative pronoun arrives wearing di in front.

• Il concerto di cui parla tutta Spoleto è quello di apertura.
  The concert all of Spoleto is talking about is the opening one.
• L’autore di cui mi sto occupando questa settimana è Calvino.
  The author I’m working on this week is Calvino.
• È un musicista di cui mi fido completamente.
  He’s a musician I trust completely.
• Non c’è niente di cui doversi preoccupare prima del concerto.
  There’s nothing to worry about before the concert.
• Il libretto di cui Sveva ha bisogno è esaurito in libreria.
  The libretto Sveva needs is sold out at the bookshop.

A quick test for any of the Italian cui functions: rewrite the relative as a standalone sentence and check what preposition the verb wants. Il concerto di cui parla tutta Spoleto rebuilds as tutta Spoleto parla di un concerto, where the verb wants di, so the relative needs di cui. L’autore di cui mi sto occupando rebuilds as mi sto occupando di un autore: same logic. If the rebuilt sentence uses a, you need a cui; if con, then con cui; and so on through the Italian cui functions.

Note that di cui has two further specialised uses: as a partitive (“of whom”, “including”) after a number, and in the frozen legal phrase di cui sopra (“above-mentioned”). Both of those land at B2 and we treat them in the focused guide on di cui as including and mentioned. For this B1 overview we stay with the basic relative use.

In cui: place and time

The third member of the Italian cui functions is in cui, and it is the most flexible of the set. It covers both physical place (the city in which, the room in which) and time (the year in which, the moment in which, the day in which). For physical place, spoken Italian usually swaps in cui for the lighter dove. For time, in cui is the only option, since Italian does not allow quando in relative clauses.

• La piazza in cui suonano l’orchestra ogni sera è quella del Duomo.
  The square where they play the orchestra every evening is the Duomo one.
• L’anno in cui Menotti fondò il festival era il 1958.
  The year Menotti founded the festival was 1958.
• Il momento in cui si abbassano le luci è il più bello della serata.
  The moment the lights go down is the best of the evening.
• La sala in cui si recita Shakespeare ha solo trecento posti.
  The hall where they perform Shakespeare has only three hundred seats.
• Il giorno in cui ho conosciuto Sveva era piovoso e freddo.
  The day I met Sveva was rainy and cold.

For the first and fourth examples (physical places) you can equally say la piazza dove suonano and la sala dove si recita. For the second, third and fifth (time slots) only in cui works: never l’anno quando, never il giorno quando. Italian also uses in cui for manner, in the fixed phrase il modo in cui (“the way in which”). Il modo come, which sounds tempting to English speakers, is wrong. So in cui, among the Italian cui functions, is the one with the widest reach.

Con cui, da cui, su cui, tra cui

Four more Italian cui functions cover the remaining everyday prepositions, and they round out the core set of Italian cui functions you need at B1. They behave identically: pick the verb’s preposition, glue it in front of cui, place the pair after the noun. None of them allow the bare-cui drop that a cui permits.

Con cui covers company, instrument, or means: people you went with, tools you worked with, vehicles you travelled with.

• La signora con cui Sveva ha condiviso il tavolo veniva da Perugia.
  The lady Sveva shared the table with was from Perugia.
• Il taxi con cui siamo arrivati dalla stazione era pieno di valigie.
  The taxi we came from the station with was full of suitcases.

Da cui covers origin, source, or the person you go to for a service (the verb andare da = “go to someone’s place”). It also appears in nascere da, derivare da, partire da, dipendere da, scappare da.

• Il vicolo da cui siamo passati porta dritto alla Rocca Albornoziana.
  The lane we came through leads straight up to the Rocca Albornoziana.
• Il dentista da cui vado a Spoleto riceve solo il martedì.
  The dentist I go to in Spoleto only sees patients on Tuesdays.
• La famiglia da cui discende il maestro era originaria di Cadegliano.
  The family the conductor comes from was originally from Cadegliano.

Su cui covers a physical surface, a topic of focus, or something you count on: scrivere su, contare su, riflettere su, basarsi su.

• Il programma su cui abbiamo segnato gli spettacoli è pieno di appunti.
  The programme on which we marked the shows is full of notes.
• L’unico amico su cui Ottavio può contare a Spoleto è Margherita.
  The only friend Ottavio can count on in Spoleto is Margherita.

Tra cui (or fra cui) introduces a sample from a wider group, where English would say “including” or “among them”.

• Gli artisti tra cui c’è anche il regista arriveranno tra poco.
  The artists, who include the director, will arrive shortly.
• Le opere tra cui dobbiamo scegliere sono cinque.
  The works we have to choose from are five.

Per cui: reason and “and so”

Among the Italian cui functions, per cui is the most stretched of all. It has two distinct lives. The first is the regular relative use after a verb that takes per: votare per, lottare per, cercare per. The second is a sentence-level connector meaning “and so”, “therefore”. Modern Italian, says Treccani, has adopted per cui alongside perciò and quindi in this connector role, and you will hear it constantly in conversation.

• Il festival per cui Spoleto è famosa nel mondo dura tre settimane.
  The festival Spoleto is famous in the world for lasts three weeks. (regular relative)
• Ecco la ragione per cui siamo arrivati qui solo adesso.
  That’s the reason we arrived here only just now. (regular relative, fixed phrase la ragione per cui)
• Il candidato per cui ho votato non è stato eletto.
  The candidate I voted for wasn’t elected. (regular relative)
• Stasera sono stanco, per cui vado a letto presto.
  I’m tired tonight, so I’m going to bed early. (sentence connector = perciò, quindi)
• Domani piove, per cui il concerto in piazza è rinviato.
  It will rain tomorrow, so the open-air concert is postponed. (sentence connector)

Treccani explains the connector use as a contraction of la ragione per cui or il motivo per cui: the antecedent is silent, the relative refers back to the whole previous sentence. This makes per cui the most versatile of the Italian cui functions. In careful written Italian some readers still prefer perciò or quindi in this slot, but in everyday speech per cui is universal. Recognise both uses and you will not be confused when one sentence inside the same paragraph uses per cui as a regular relative and the next uses it as “therefore”.

Il cui, la cui, i cui, le cui: whose

The possessive member of the Italian cui functions translates English whose. Unlike the other Italian cui functions, this one takes an article in front of cui. It always appears as article + cui + noun, and the article agrees with the noun that follows cui, not with the owner. This is the rule English speakers get wrong most often, because in English the possessive marker matches the owner, not the thing owned.

• Il compositore il cui ritratto è in cattedrale è morto a Spoleto.
  The composer whose portrait is in the cathedral died in Spoleto.
• La cantante la cui voce ha aperto la stagione è siciliana.
  The singer whose voice opened the season is Sicilian.
• Gli artisti i cui nomi sono in cartellone arrivano da tutta Europa.
  The artists whose names are on the programme come from all over Europe.
• Le opere le cui prove cominciano oggi vanno in scena venerdì.
  The works whose rehearsals start today open on Friday.
• Sveva, la cui famiglia vive a Perugia, viene a Spoleto ogni luglio.
  Sveva, whose family lives in Perugia, comes to Spoleto every July.

Look at the second example. The singer is feminine, but the article is la only because the thing possessed (voce) happens to be feminine. If the same singer’s nome were the topic, you would say la cantante il cui nome appare sul programma, with il agreeing with nome. Look at the last example: Sveva is feminine, famiglia is feminine, so la cui, but if she had several brothers we would say Sveva, i cui fratelli vivono a Perugia. The possessor’s gender is irrelevant. Always ignore the owner and look at the noun that follows cui.

The possessive variant of the Italian cui functions can also appear after a preposition, although the construction is rare and slightly stiff: lo scrittore nella cui casa ho dormito (“the writer in whose house I slept”), il regista del cui film abbiamo parlato (“the director of whose film we spoke”). The simpler alternative is to recast: lo scrittore in casa del quale ho dormito or, even better, lo scrittore a casa del quale ho dormito. In a B1 essay either version is fine; in conversation Italians often rephrase the whole sentence to avoid the structure altogether.

Cui or il quale: when natives switch

Every one of the Italian cui functions described so far has a parallel built on il quale, which agrees in gender and number with the antecedent. The two are interchangeable in meaning. The difference is register and length. Treccani notes that “as indirect complement, the type articulated-preposition + quale is just as common as the type simple-preposition + cui”: il funzionario al quale ho parlato equals il funzionario a cui ho parlato; il film del quale mi dicevi equals il film di cui mi dicevi.

Three situations where natives quietly switch from cui to il quale:

• Distant antecedent. When the noun and the relative are separated by a long phrase, the agreement of il quale makes the connection clear. L’unico spettacolo del festival, programmato in piazza Duomo per la sera del 5 luglio, al quale abbiamo deciso di andare is easier to parse than the same sentence with cui.
• After numerals and indefinites. Ho provato sette violini, tre dei quali stonati is preferred to tre di cui stonati, which sounds clipped.
• Formal writing and journalism. Court rulings, academic papers and quality newspapers reach for il quale more often, partly for clarity and partly for register.

In everyday speech and everyday writing, cui wins on lightness. Use it as your default for all the Italian cui functions and switch to il quale only when one of the three situations above applies. The Italian cui functions handle nine cases out of ten without help.

Cheat sheet: all the Italian cui functions in one table

One table to keep open while you write your next paragraph. The pattern across all Italian cui functions is always preposition + cui + verb that wants that preposition.

Form	Function	Triggered by	Example
a cui (or bare cui)	indirect object	scrivere a, telefonare a, dare a, chiedere a	l’amico a cui ho scritto
di cui	topic, source, need	parlare di, fidarsi di, aver bisogno di	il libro di cui ti parlavo
in cui	place and time	abitare in, viare in, l’anno in cui, il momento in cui	la città in cui vivo
con cui	company, instrument	uscire con, viaggiare con, scrivere con	l’amica con cui sono partita
da cui	origin, source person	venire da, partire da, andare da (al dentista)	il dentista da cui vado
su cui	surface, topic, reliance	contare su, scrivere su, riflettere su	la mensola su cui ho messo il libro
per cui (relative)	reason, purpose	la ragione per cui, votare per	la ragione per cui non sono venuto
per cui (connector)	“and so”, “therefore”	sentence-level, equals perciò / quindi	sono stanco, per cui vado a letto
tra cui / fra cui	“among them”, “including”	partitive after a group noun	gli ospiti, tra cui il sindaco
il cui / la cui / i cui / le cui	possessive (“whose”)	article matches the thing possessed	lo scrittore il cui libro è uscito

Three common mistakes

Three errors with the Italian cui functions flag a B1 essay as written by a learner. Spotting and fixing them is fast, and the same three mistakes recur across all the Italian cui functions.

Mistake 1. Stranding the preposition. This is the cardinal error across the Italian cui functions. Wrong: il concerto cui sono andato a. Wrong: l’amica con la quale sono uscita con. Italian never lets a preposition trail off at the end of a relative clause. Correct: il concerto a cui sono andato, l’amica con cui sono uscita. The preposition must precede cui and stay glued to it.

Mistake 2. Articulating the preposition before cui. This second error trips up learners across all the Italian cui functions. Wrong: il libro del cui ti parlavo. Wrong: l’amico al cui ho scritto. The simple preposition stays simple in front of cui: never del cui, al cui, nel cui, sul cui, dal cui. The articulated form (del, al, nel, sul, dal) belongs only with il quale: il libro del quale ti parlavo, l’amico al quale ho scritto. With cui, plain di, a, in, su, da.

Mistake 3. Matching il cui with the owner instead of the noun. Wrong: Sveva, il cui famiglia vive a Perugia. Sveva is feminine, but the article must match famiglia, which is feminine: Sveva, la cui famiglia vive a Perugia. Same logic in the reverse: an article must agree with the noun even when the owner is a different gender, as in la pianista il cui repertorio comprende Liszt, where il matches repertorio, not the female pianist. Always look at the noun that follows cui, never at the owner.

Dialogue at the Spoleto Festival

Sveva and Ottavio meet for an aperitivo at the caffè della cattedrale during the Festival dei Due Mondi, the international performing-arts festival that fills Spoleto every July. Count the Italian cui functions as they appear: nearly the whole set turns up in fifteen minutes of conversation.

Count the forms Sveva and Ottavio use: su cui, di cui, con cui, a cui, per cui, da cui, in cui, il cui, le cui. Nine of the Italian cui functions, all of them deployed without effort, and the whole set of Italian cui functions feels natural in context. The last sentence even slips in two per cui: the first one is a regular relative (Spoleto is famous for the festival), the second one is the sentence connector (“therefore”).

Test your understanding

Take the quiz below to test what you have learned about the Italian cui functions, drilling each preposition + cui pattern in context.

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Frequently asked questions

Six questions about the Italian cui functions come up in every B1 cohort, and the answers below cover the corners of the Italian cui functions that students keep returning to. The answers below draw on the Treccani entry on pronomi relativi and the Accademia della Crusca consultation on the relative pronoun cui.

Related guides

Three guides that pair with the Italian cui functions, plus an institutional reference on the broader relative pronoun system that hosts the Italian cui functions.

• Italian Relative Pronouns: Che, Cui, Il Quale, Whose: the full hub on the relative pronoun system, of which this post is the focused spin-off on cui.
• Di Cui in Italian: Including and Mentioned: B2 deep-dive on the partitive use (di cui due minorenni) and the legal di cui sopra.
• Italian Reduced Relatives: Una Lettera Arrivata: B2 sister post on how Italian shortens relative clauses without a finite verb.
• Accademia della Crusca: Uso del pronome relativo cui: institutional consultation on the use of the relative pronoun cui.