Complete Italian Course · Grammar Comparison
Che vs Cui
One test decides it: is there a preposition right before the relative pronoun? Here's the rule, plus what to learn next once these two feel automatic.
CEFR Level A2🔑
The Core Rule
🔑 The Rule
Use che for "that/which/who" when there's no preposition involved — as the subject or object of the clause. Use cui whenever a preposition comes right before the relative pronoun (a cui, di cui, con cui, in cui...), since che can never follow a preposition. Both are invariable — they never change form for gender or number — and unlike English, Italian never drops either one.
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Side by Side
| Che | Cui | |
|---|---|---|
| Role | Subject or object of the clause | Object of a preposition |
| Preposition before it? | Never | Always |
| Changes form? | No — invariable | No — invariable |
| Can English drop it? | Yes ("the book I read") — Italian can't | Yes ("the person I wrote to") — Italian can't |
| Example | Il film che ho visto | Il libro di cui parlo |
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Examples
- Conosco un ristorante che serve pesce fresco. — I know a restaurant that serves fresh fish. (che, subject)
- La torta che hai fatto era buonissima. — The cake (that) you made was delicious. (che, object)
- L'ufficio in cui lavoro è vicino a casa. — The office (in which) I work is close to home. (cui, after "in")
- Gli amici con cui viaggio sono simpatici. — The friends (with whom) I travel are nice. (cui, after "con")
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Common Mistakes
- Dropping che or cui the way English drops "that/which/whom." Italian never drops che, and never drops cui or the preposition before it — both are always spelled out in full.
- Using che directly after a preposition (something like "la persona a che ho scritto") — che simply cannot follow a preposition; the sentence needs cui instead.
- Confusing prepositional cui with possessive cui. Di cui, a cui, in cui ("which/whom," after a preposition) and il cui / la cui ("whose," a possessive) are different constructions that happen to share the word cui.
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Edge Cases
- Che and cui's invariance is itself a source of ambiguity in more complex sentences — this is precisely why il quale exists as a formal alternative (its own gender/number endings can disambiguate what cui alone can't). See Il Quale vs Il Cui for the next step up.
- Possessive cui is a separate construction, fully covered on that same page.
- English's optional relative pronoun has no Italian equivalent — a structural, not just stylistic, difference worth stating plainly, since omitting che/cui entirely (mirroring casual English) is one of the most common English-interference errors at this level.
Questions
Frequently asked
Can I drop che or cui the way English drops "that" or "which"?
No — English can drop the relative pronoun ("the book I read," "the person I wrote to"), but Italian never can. Che and cui — and the preposition before cui — must always be spelled out in full.
Why does che become cui in some sentences?
It's not that che "becomes" cui — they're used in different roles. Che is the subject or object of the relative clause with no preposition involved. The moment a preposition needs to attach to the relative pronoun (a, di, con, per, in...), che can't be used at all, and cui takes over instead: a cui, di cui, con cui, in cui.
Is cui the same word whether it means "which/whom" or "whose"?
It's spelled the same, but they're genuinely different constructions. Prepositional cui (di cui, a cui, in cui) replaces "which/whom" after a preposition. Possessive cui (il cui, la cui) instead means "whose" — a different grammatical role that happens to share the same word.
Do che and cui ever change form for gender or number?
No — both are invariable. Unlike many other Italian words, che and cui stay exactly the same regardless of whether they refer to something masculine, feminine, singular, or plural.
What's the difference between cui and il quale?
Il quale is a more formal alternative to cui that does change form for gender and number (il quale, la quale, i quali, le quali), which lets it resolve ambiguity that invariable cui sometimes can't in more complex sentences. It's the natural next step up once che and cui are comfortable.
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Where to Learn More
Che's first introduction, including the "Italian never drops che" rule.
The primary teaching lesson: che as subject/object in full, and cui after prepositions.
The natural next step: il quale as the formal disambiguating alternative, and the separate possessive cui ("whose") construction.