Learn Hardcore Italian: Italo legge un libro giallo in giardino. - Italo reads a yellow book in the garden.

In Italian most descriptive adjectives—especially colors, shapes and sizes—follow the noun they modify.
• libro giallo = “yellow book”
• If you put giallo before, it often becomes poetic or emphatic.

Does giallo always mean “yellow”?

Literally, yes: giallo = “yellow.”
However, in publishing jargon un giallo also means “a mystery novel,” because early mystery paperbacks in Italy had yellow covers.

Why is the indefinite article un used before libro?

Because libro is a masculine singular noun, and the speaker is not referring to a specific book.
• Masculine singular → un (a/an)
• If it were feminine singular (e.g. casa), you’d say una casa.

How do gender and number agreement work in un libro giallo?

Everything agrees with libro (masculine singular):
• Article: un (masc. sing.)
• Noun: libro (masc. sing.)
• Adjective: giallo (masc. sing.)
For plural books you’d say dei libri gialli (masc. pl.).

What form of the verb is legge, and why is it used here?

Legge is the third-person singular present indicative of leggere (“to read”).
• Italo (he) → legge (he reads)

Why is the preposition in used before giardino, and why no article?

In indicates location “inside” or “within” an area. With generic or habitual locations, Italian often omits the article:
• in giardino = “in (the) garden” (speaking generally)
If you want a specific garden you’d say nel giardino (“in the garden”), using nel = in + il.

How would you turn Italo into a pronoun in this sentence?

Replace Italo (proper name) with the subject pronoun lui (he):
• Lui legge un libro giallo in giardino.

Could you drop giallo and still have a correct sentence?

Yes.
• Italo legge un libro in giardino.
This simply omits the detail about the book’s color (or genre).