L'operaio rinforza la muratura con il cemento.

Because operaio begins with a vowel. In Italian, the masculine singular definite article il becomes l' before a vowel for smoother pronunciation.

So:

• il ragazzo
• l'operaio

The apostrophe shows that the vowel in il has dropped.

Operaio is a noun meaning worker and it is masculine singular.

Its feminine form is operaia.

So:

• l'operaio = the male worker / the worker
• l'operaia = the female worker

In this sentence, l'operaio is the subject.

Rinforza is the third-person singular present tense of the verb rinforzare, meaning to strengthen or to reinforce.

So:

• io rinforzo = I strengthen
• tu rinforzi = you strengthen
• lui/lei rinforza = he/she strengthens

In the sentence, l'operaio rinforza means the worker strengthens.

Muratura is a feminine singular noun, so it takes the feminine singular definite article la.

• la muratura

This noun usually refers to masonry, brickwork, or wall structure, not just a single wall. It often refers to the built stone or brick construction as a material structure.

They are related, but not the same.

• muro = wall
• muratura = masonry, brickwork, wall construction

So muro is usually a specific wall, while muratura refers more to the structural masonry or built wall material. In a construction context, muratura is often the more natural word.

Con means with, and here it introduces the material or means used to do the action.

• con il cemento = with the cement

Italian often uses the definite article with materials and common nouns in places where English might or might not use the. So con il cemento is very natural.

It means the worker is reinforcing the masonry using cement.

Sometimes yes, but it would sound less specific and less natural in many ordinary contexts.

• con il cemento suggests a definite material being used, or simply the normal Italian way of referring to the material in this context.
• con cemento can sound more general, like using cement as a material type.

In everyday Italian, con il cemento is the safer and more idiomatic choice for this sentence.

No, Italian word order is fairly flexible, although this version is the most neutral and natural:

• L'operaio rinforza la muratura con il cemento.

You could move parts around for emphasis, for example:

• Con il cemento, l'operaio rinforza la muratura.

That puts more focus on with the cement. But the original order is the standard one for a simple statement.

Yes, Italian often drops subject pronouns, but here the subject is not a pronoun; it is the noun l'operaio.

You could say:

• Rinforza la muratura con il cemento.

Grammatically, that means He/She strengthens the masonry with the cement or is strengthening..., depending on context.

But if you specifically want to say the worker, you keep l'operaio.

The stress is on the for syllable:

• rin-FOR-za

A rough English-style guide:

• reen-FOR-tsa

The z in rinforza is pronounced like ts in many standard pronunciations.

Because each noun here is singular:

• l'operaio = the worker
• la muratura = the masonry
• il cemento = the cement

The verb rinforza is also singular because it agrees with the singular subject l'operaio.

If the subject were plural, the verb would change too:

• Gli operai rinforzano la muratura con il cemento.
• The workers strengthen the masonry with the cement.

It follows a very common pattern:

• Subject: L'operaio
• Verb: rinforza
• Direct object: la muratura
• Prepositional phrase: con il cemento

So the structure is:

subject + verb + object + with-phrase

That is one of the most common and natural sentence patterns in Italian.