L'operaio leviga il parquet.

Because operaio begins with a vowel. In Italian, il becomes l' before most singular masculine nouns that start with a vowel.

So:

• il libro
• l'operaio

This is just the normal article form, not a special meaning.

Operaio usually means a worker, especially a manual worker, laborer, or factory/construction worker rather than an office employee.

It is a masculine singular noun.

Related forms:

• l'operaio = the male worker
• gli operai = the workers
• l'operaia = the female worker
• le operaie = the female workers / the women workers

Leviga is the present indicative, third person singular, of levigare.

So it means:

• he smooths / sands / polishes
• she smooths / sands / polishes
• it smooths / sands / polishes

In this sentence, the subject is l'operaio, so leviga means the worker smooths/sands/polishes.

A quick pattern:

• io levigo = I smooth
• tu levighi = you smooth
• lui/lei leviga = he/she smooths
• noi levighiamo = we smooth
• voi levigate = you all smooth
• loro levigano = they smooth

This is a spelling rule for verbs ending in -gare.

Italian adds h before e or i to keep the hard g sound.

So:

• levigo
• levighi
• leviga
• levighiamo
• levigate
• levigano

Why?

• Before a, o, and u, g already sounds hard.
• Before e and i, Italian spelling would normally soften it, so an h is added to keep the hard sound.

That is why leviga does not need an h, but levighi does.

Because parquet is a noun, and here it is a specific thing: the parquet floor.

So il parquet means the parquet or the parquet floor.

Italian often uses the definite article in places where English might also use the, and sometimes even where English would omit it in other contexts. In this sentence, il parquet is completely natural.

Yes, parquet is a loanword, originally from French, but it is commonly used in Italian.

In Italian, it is usually treated as:

• masculine
• often invariable in the plural

So you commonly get:

• il parquet
• i parquet

Even though it is a foreign word, it still takes a normal Italian article.

In Italian, it is generally pronounced approximately par-KET, with the final t pronounced.

That may feel unusual to English speakers, since many French final consonants are silent, but in Italian borrowed words are often pronounced according to Italian usage.

Because Italian usually does not need subject pronouns when the verb form already makes the person clear.

Here, though, the subject is not hidden at all, because it is explicitly stated:

• L'operaio leviga il parquet.

Italian would only add lui for emphasis or contrast, for example:

• Lui leviga il parquet, non io.
  He smooths the parquet, not me.

So the lack of a pronoun is completely normal.

This sentence uses the most neutral Italian word order:

• subject + verb + object

So:

• L'operaio = subject
• leviga = verb
• il parquet = direct object

Italian word order can change for emphasis, but this version is the standard, straightforward one.

For example, Il parquet lo leviga l'operaio is possible in a marked or emphatic context, but much less neutral.

Not always exactly. Levigare can mean to smooth, to sand, to polish, or to make a surface even/smooth, depending on context.

With parquet, it often suggests the process of sanding or smoothing the wooden floor surface.

So the precise English choice may vary, but the Italian verb is perfectly natural here.

Yes. In Italian, parquet commonly refers to a wooden floor or parquet flooring in general, not only the decorative pattern.

So in a sentence like this, learners should understand it as the floor surface the worker is treating.

They are:

• l'operaio → gli operai
• il parquet → i parquet
• leviga → levigano if the subject becomes plural

So:

• Gli operai levigano i parquet.

That means the workers smooth/sand the parquet floors.