Questo coccio è poroso.

Because coccio is a masculine singular noun, and questo has to agree with it.

Agreement with questo works like this:

• questo = masculine singular
• questa = feminine singular
• questi = masculine plural
• queste = feminine plural

So:

• questo coccio = this shard / this piece of pottery

If the noun were feminine, you would use questa instead.

Coccio most commonly means a piece of broken pottery, a potsherd, or sometimes a clay/earthenware piece or object, depending on context.

A learner may notice that it is not one of the most common everyday nouns, so it can feel a bit specific. In different contexts, coccio can also have other uses, including colloquial ones, but in a simple sentence like this it usually refers to a pottery fragment or earthenware object.

So the important thing here is:

• it is a masculine noun
• it refers to something made of pottery/clay/earthenware

Because questo already functions as a determiner, like this in English.

In Italian, you normally say:

• questo coccio = this shard

not:

• il questo coccio

That sounds wrong in standard Italian.

So questo replaces the article here.

The accent is important because it distinguishes two different words:

• è = is
• e = and

So:

• Questo coccio è poroso = This piece of pottery is porous.
• Questo coccio e poroso would be a spelling mistake.

Also, è is the third person singular form of the verb essere (to be).

Because adjectives in Italian usually agree with the noun they describe.

Since coccio is masculine singular, the adjective must also be masculine singular:

• coccio poroso

Here are the common forms of poroso:

• poroso = masculine singular
• porosa = feminine singular
• porosi = masculine plural
• porose = feminine plural

For example:

• Questo coccio è poroso
• Questa pietra è porosa

Yes. In Italian, descriptive adjectives often come after the noun:

• un materiale poroso
• un oggetto fragile
• un coccio poroso

In your sentence, the adjective comes after the verb è, so it works like English:

• Questo coccio è poroso = This shard is porous.

That word order is completely normal.

A native English speaker may wonder about the cc.

Coccio is pronounced roughly like KOH-cho.

A few helpful points:

• co sounds like ko
• cci before i makes a ch sound, like in church
• the double cc is pronounced more strongly than a single consonant

So it is approximately:

• coccio → KOH-cho

Not:

• KOH-see-oh
• KOH-kee-oh

Because Italian normally does not use a separate subject pronoun when it is unnecessary.

The noun phrase questo coccio already tells you what the subject is, so adding a pronoun like esso would sound unnatural in ordinary speech.

Italian usually prefers:

• Questo coccio è poroso

rather than something like:

• Questo coccio, esso è poroso

Also, esso is much less common in everyday spoken Italian than English it.

Yes, that is a very natural literal translation.

Word by word:

• Questo = this
• coccio = shard / piece of pottery / earthenware piece
• è = is
• poroso = porous

So the structure matches English quite closely.

Yes, but Questo coccio è poroso is the most neutral and natural order.

Italian can sometimes change word order for emphasis, for example:

• È poroso, questo coccio

This sounds more marked, as if you are emphasizing poroso.

For a basic statement, though, the standard order is:

• Questo coccio è poroso

Here it is acting as a demonstrative determiner—in traditional grammar, often called a demonstrative adjective—because it directly accompanies a noun:

• questo coccio

If it stood alone, it would be a pronoun:

• Questo è poroso = This is porous.

So in your sentence, questo is attached to coccio, not standing by itself.