La pettorina è accanto al collare.

Because pettorina is a feminine singular noun in Italian.

• la = the for feminine singular nouns
• il = the for masculine singular nouns

So:

• la pettorina
• not il pettorina

Many Italian nouns ending in -a are feminine, and pettorina follows that common pattern.

In this kind of sentence, pettorina usually means a harness, especially for a dog. Depending on context, the word can also mean other things in Italian, such as a bib-like garment or a training vest, but here it most naturally means harness.

So if this is about pet equipment:

• pettorina = harness
• collare = collar

The accent is important because è means is.

Compare:

• è = is
• e = and

So:

• La pettorina è accanto al collare = The harness is next to the collar.
• La pettorina e il collare = The harness and the collar.

The accent helps distinguish two very common words.

Because accanto normally uses the preposition a:

• accanto a = next to / beside

So the full structure is:

• accanto a + il collare

Then a + il combines into al.

That is why you get:

• accanto al collare

not:

• accanto il collare

Al is a contraction of:

• a + il = al

This is very common in Italian.

Other common contractions include:

• a + la = alla
• a + i = ai
• a + gli = agli
• a + le = alle

So in your sentence:

• accanto a il collare becomes accanto al collare

The ending -e does not automatically tell you whether a noun is masculine or feminine. Collare is a masculine noun, so it takes il in the singular:

• il collare

Because it comes after a, you get:

• a + il collare = al collare

So even though collare ends in -e, it is still masculine.

They are very similar, and in many situations both can mean next to or near.

• accanto a often suggests right beside
• vicino a can mean near and may be a little broader

Examples:

• La pettorina è accanto al collare = The harness is right next to the collar.
• La pettorina è vicino al collare = The harness is near / next to the collar.

In everyday speech, the difference is often small.

This is the standard Italian order:

• subject: La pettorina
• verb: è
• location expression: accanto al collare

So it works like:

• The harness
  • is
    • next to the collar

Italian often follows this straightforward pattern in simple statements.

Normally, no. In standard Italian, you would usually keep the articles here:

• La pettorina è accanto al collare

Italian uses definite articles more often than English does. When talking about specific objects like a harness and a collar, the articles sound natural and expected.

Without the articles, the sentence sounds unnatural in normal usage.

A simple pronunciation guide is:

la pet-toh-REE-na eh ak-KAN-to al kol-LAH-reh

A few notes:

• tt in pettorina is pronounced as a clear double consonant
• è sounds like eh
• cc in accanto sounds like a hard k sound here
• collare has stress on -la-

A rough IPA version is:

[la pettoˈriːna ɛ akˈkanto al kolˈlaːre]

Yes. That would also be grammatically correct. It just changes which item is the subject:

• La pettorina è accanto al collare = The harness is next to the collar.
• Il collare è accanto alla pettorina = The collar is next to the harness.

Both describe the same physical relationship, but they focus on different nouns.

You would make both the noun and the article plural, and adjust the contraction if needed.

Singular:

• La pettorina è accanto al collare.

Plural:

• Le pettorine sono accanto ai collari.

Changes:

• la pettorina → le pettorine
• è → sono
• al collare → ai collari

So the full plural sentence is:

Le pettorine sono accanto ai collari.