Learn Hardcore Italian: Sul treno c’è un posto vuoto. - There is an empty seat on the train.

Sul is the contraction of the preposition su (“on”) and the masculine singular definite article il (“the”). So su + il = sul, meaning “on the”.

Why is it su + il (sul) rather than su + lo?

In Italian the definite article il is used before most consonants. Lo is reserved for nouns that start with z, s + consonant, gn, ps, x or y. Since treno begins with tr, you pair su with il, giving sul treno.

What is c’è, and why does it have an apostrophe?

c’è is a contraction of the adverbial pronoun ci (meaning “there”) plus the verb è (third-person singular of essere, “to be”). We use an apostrophe because the vowel i from ci is dropped before the vowel è.

Why do we say c’è instead of ci sono here?

c’è is singular, so it’s used when the following noun is singular (un posto). If you had multiple seats, you’d say ci sono posti vuoti (“there are empty seats”).

Why is the indefinite article un and not uno?

Italian uses un before most masculine nouns and uno only before masculine nouns starting with z, s + consonant, ps, gn, x or y. Since posto starts with a simple consonant p, the correct form is un posto.

Why is the adjective vuoto placed after the noun posto?

In Italian descriptive adjectives normally follow the noun they modify. So you get posto vuoto (“empty seat”). Placing the adjective before the noun is possible but often changes the nuance or emphasis.

What’s the difference between posto vuoto and posto libero?

Both can indicate an available seat. vuoto literally means “empty” (nobody is sitting there). libero means “free” or “available.” In everyday speech posto libero is more common when talking about occupancy, while posto vuoto stresses that it’s physically empty.