La macelleria è accanto alla pescheria.

Because è is the verb essere (to be) in the he/she/it is form.

• è = is
• e = and

So in this sentence:

• La macelleria è accanto alla pescheria. = The butcher’s shop is next to the fish shop.

The accent is very important because it changes the meaning.

Because macelleria and pescheria are both feminine singular nouns, so they take the feminine singular definite article la.

• la macelleria
• la pescheria

In Italian, articles are used more often than in English, so where English might say butcher’s shop or fish shop, Italian normally says the butcher’s shop / the fish shop.

Because in Italian, a + la combines into alla.

This is a very common contraction:

• a + il = al
• a + lo = allo
• a + la = alla
• a + l’ = all’
• a + i = ai
• a + gli = agli
• a + le = alle

Here, the expression is accanto a (next to), and the next noun is la pescheria, so:

• accanto a + la pescheria
• becomes
• accanto alla pescheria

Accanto a is a fixed expression meaning:

• next to
• beside

So:

• accanto alla pescheria = next to the fish shop

It is useful to learn accanto a as one unit, because the a is part of the expression.

Examples:

• La banca è accanto al supermercato. = The bank is next to the supermarket.
• Sono seduto accanto a Maria. = I’m sitting next to Maria.

Actually, the word order here is very close to English:

• La macelleria = subject
• è = verb
• accanto alla pescheria = location phrase

So it follows the same basic pattern as:

• The butcher’s shop is next to the fish shop.

Italian often has flexible word order, but this sentence uses the most neutral and natural order.

Yes. The ending -eria often appears in words for shops or places associated with a trade or product.

For example:

• macelleria = butcher’s shop
• pescheria = fish shop / fishmonger's
• panetteria = bakery
• gelateria = ice cream shop

So macelleria comes from macellaio (butcher) and pescheria is related to pesce (fish).

Usually, yes: nouns ending in -a are often feminine, and here that pattern is correct.

So:

• la macelleria
• la pescheria

Their plural forms are also feminine:

• le macellerie
• le pescherie

As a beginner, it is a good habit to learn nouns together with their article:

• la macelleria
• la pescheria

Yes. Vicino a is another very common way to say near or close to.

So both are possible:

• La macelleria è accanto alla pescheria. = The butcher’s shop is next to the fish shop.
• La macelleria è vicino alla pescheria. = The butcher’s shop is near the fish shop.

The difference is small:

• accanto a usually suggests right next to
• vicino a can mean near, not necessarily immediately beside

A simple pronunciation guide is:

La ma-cel-le-RI-a è ac-CAN-to al-la pe-sche-RI-a.

A few helpful points:

• c before e in macelleria sounds like ch in English check
• sch in pescheria sounds like sk
• the stress is on -ri- in both macelleria and pescheria
• è is pronounced like eh

So:

• macelleria ≈ ma-chel-leh-REE-ah
• pescheria ≈ pes-keh-REE-ah

No, that would sound unnatural and incorrect in standard Italian.

With common nouns like these, Italian normally needs the articles:

• La macelleria è accanto alla pescheria.

Italian uses articles more regularly than English does, especially with places, professions as nouns, and many general references.

Yes, absolutely.

Because the relationship is mutual, both sentences are correct:

• La macelleria è accanto alla pescheria.
• La pescheria è accanto alla macelleria.

They mean almost the same thing, but the focus changes depending on which shop you mention first.