Indefinite Articles in Italian

Overview

Italian has four indefinite articles — un, uno, una, un' — corresponding to English "a" or "an." Just like with definite articles, you must choose the correct form based on two factors: the gender of the noun (masculine or feminine) and its first letter (or first letters). Unlike definite articles, indefinite articles exist only in the singular — there is no plural indefinite article in Italian (the partitive articles dei, degli, delle serve a similar role but are a separate topic).

This is a core A1 topic that you will use in virtually every conversation. Ordering "a coffee," describing "a friend," or mentioning "a student" all require selecting the right indefinite article. The selection rules closely mirror those for definite articles, so if you have already studied Definite Articles, you will recognize the same first-letter patterns here.

Before tackling indefinite articles, make sure you are comfortable with Gender of Nouns, since knowing whether a noun is masculine or feminine is the first step in choosing the correct article.

How It Works

The Complete Article Table

Article	Gender	Used Before	Example
un	Masculine	Most consonants and all vowels	un libro (a book), un amico (a friend, m)
uno	Masculine	s + consonant, z, gn, ps, pn, x, y	uno studente (a student), uno zaino (a backpack)
una	Feminine	Any consonant	una casa (a house), una strada (a street)
un'	Feminine	Any vowel	un'amica (a friend, f), un'idea (an idea)

Step-by-Step Selection

1. Determine gender. Is the noun masculine or feminine? (See Gender of Nouns.)
2. Look at the first letter(s) of the noun.
   • Masculine: use un for most consonants and all vowels, uno for the special consonant clusters (s+consonant, z, gn, ps, pn, x, y).
   • Feminine: use una for consonants, un' (with apostrophe) before a vowel.

Key Difference from Definite Articles

Notice an important asymmetry: masculine un does not take an apostrophe before vowels (un amico), while feminine un' does (un'amica). This is the opposite of what many learners expect and is one of the most common sources of mistakes.

Why "uno" Mirrors "lo"

The special clusters that trigger uno are exactly the same ones that trigger lo in definite articles: s+consonant, z, gn, ps, pn, x, y. If a masculine noun takes lo as its definite article, it takes uno as its indefinite article.

Examples in Context

Italian	English	Why This Article
Ho un libro nuovo.	I have a new book.	libro starts with l (consonant), masculine → un
C'è uno studente in classe.	There is a student in class.	studente starts with s + consonant, masculine → uno
Voglio una pizza.	I want a pizza.	pizza starts with consonant, feminine → una
Ha un'idea brillante.	She has a brilliant idea.	idea starts with vowel, feminine → un'
Un amico mi ha chiamato.	A friend (m) called me.	amico starts with vowel, masculine → un (no apostrophe)
Ho visto uno zaino rosso.	I saw a red backpack.	zaino starts with z, masculine → uno
Cerco una stanza.	I'm looking for a room.	stanza starts with consonant, feminine → una
È un'occasione unica.	It's a unique opportunity.	occasione starts with vowel, feminine → un'
Conosco uno psicologo.	I know a psychologist.	psicologo starts with ps, masculine → uno
Vuoi un caffè?	Do you want a coffee?	caffè starts with consonant, masculine → un
Ho comprato un orologio.	I bought a watch.	orologio starts with vowel, masculine → un (no apostrophe)
C'è una farmacia qui vicino?	Is there a pharmacy nearby?	farmacia starts with consonant, feminine → una
Ho un'amica italiana.	I have an Italian friend (f).	amica starts with vowel, feminine → un'

Common Mistakes

Adding an apostrophe to masculine "un"

• Wrong: un'amico
• Right: un amico
• Why: The masculine form un never takes an apostrophe, even before a vowel. Only the feminine form uses the apostrophe: un'amica.

Using "un" before s + consonant

• Wrong: un studente, un specchio
• Right: uno studente, uno specchio
• Why: Masculine nouns beginning with s followed by another consonant require uno, not un. The same clusters that trigger lo trigger uno.

Forgetting the apostrophe on feminine "un'"

• Wrong: una amica, una idea
• Right: un'amica, un'idea
• Why: When a feminine noun begins with a vowel, una must elide to un'. Omitting the apostrophe is a spelling error.

Confusing "un" (masculine) and "un'" (feminine)

• Wrong: un amica (meaning a female friend)
• Right: un'amica
• Why: Without the apostrophe, un amica looks masculine. The apostrophe signals that the original article was una (feminine), not un (masculine). This distinction is important in writing.

Using indefinite articles in the plural

• Wrong: un libri, una case
• Right: dei libri, delle case (or simply libri, case)
• Why: Italian indefinite articles are singular only. For "some books" or "some houses," use partitive articles or drop the article entirely.

Practice Tips

1. Pair with your definite article knowledge. For every noun, practice both forms side by side: "il libro → un libro," "lo studente → uno studente," "l'amica → un'amica." This reinforces the parallel patterns and makes the rules feel like one unified system.

2. Focus on the apostrophe distinction. Write ten masculine vowel-nouns and ten feminine vowel-nouns with their indefinite articles. Seeing "un amico" next to "un'amica" repeatedly trains your hand and eye to notice the difference automatically.

3. Use flashcards with articles included. When learning new vocabulary, always write the noun with both its definite and indefinite article: "lo zaino / uno zaino." This prevents guessing and builds correct article habits from day one.

Related Concepts

• Prerequisite: Gender of Nouns — you must know a noun's gender before choosing its article
• Related: Definite Articles — il, lo, la, l', i, gli, le follow the same first-letter rules