Il sottotacco protegge il tacco.

Literally, sotto means under and tacco means heel, so sottotacco is something like under-heel.

In actual usage, il sottotacco refers to a heel cap, heel protector, or piece attached under the heel of a shoe. So it is a practical shoe-related word, not just a transparent combination you would freely build in any context.

Because both sottotacco and tacco are masculine singular nouns.

So:

• il sottotacco = the heel cap / the protector under the heel
• il tacco = the heel

In Italian, the definite article usually appears where English also has the, and sometimes even where English would leave it out.

The subject is il sottotacco, because it is the thing doing the action.

The verb is protegge = protects, so the sentence structure is:

• Il sottotacco = subject
• protegge = verb
• il tacco = direct object

So the meaning is: The heel cap protects the heel.

Because it is the third-person singular form of the verb proteggere.

Here is the pattern in the present tense:

• io proteggo = I protect
• tu proteggi = you protect
• lui/lei protegge = he/she/it protects

Since il sottotacco is a singular noun, Italian uses the he/she/it form: protegge.

Because proteggere is a direct transitive verb in Italian, just as to protect is in English.

So you say:

• proteggere qualcosa = to protect something

That is why il tacco comes directly after the verb as the object, with no preposition:

• Il sottotacco protegge il tacco.

The ending -o often suggests a masculine singular noun, and that is true here:

• il tacco
• il sottotacco

But it is better to think of -o = often masculine, not always masculine as an absolute rule. Italian has exceptions. In this sentence, though, both are straightforward masculine singular nouns.

Their regular plurals are:

• il tacco → i tacchi
• il sottotacco → i sottotacchi

Notice that -co here becomes -chi in the plural:

• tacco → tacchi
• sottotacco → sottotacchi

So a plural sentence would be: I sottotacchi proteggono i tacchi.

A helpful approximation is:

soht-toh-TAK-ko

A few useful points:

• tt is pronounced as a doubled consonant, with a stronger, longer t
• cc before o sounds like k, so tacco sounds like TAK-ko
• the stress is on tac

So:

• tacco = TAK-ko
• sottotacco = soht-toh-TAK-ko

Double consonants are very important in Italian pronunciation and sometimes meaning.

In this sentence:

• sottotacco has tt
• protegge has gg

These doubled consonants are pronounced more strongly than single ones. English speakers often under-pronounce them, but in Italian they matter.

For example:

• taco and tacco would not sound the same in Italian
• protegge is pronounced with a stronger gg sound than a single g

You do not need to exaggerate dramatically, but you should clearly hold the consonant a little longer.

Yes, but the normal, neutral order is:

Il sottotacco protegge il tacco.

This is the standard subject + verb + object order.

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

• Il tacco lo protegge il sottotacco.

That would sound more marked or contrastive, something like: It’s the heel that the heel cap protects.

For a learner, the original sentence is the most natural and safest version.

Usually, tacco refers to the heel of a shoe, especially in everyday contexts like this one.

However, depending on context, tacco can also refer to a heel more generally. Still, in this sentence, because of sottotacco, the shoe meaning is very clear.

So here:

• tacco = the heel of the shoe
• sottotacco = the part under that heel

Yes, that is a very good way to think about it.

It is made from:

• sotto = under
• tacco = heel

Italian often forms compound nouns like this. Sometimes the meaning is easy to guess from the parts, but you should still learn the whole word as a vocabulary item, because the exact real-world meaning may be more specific than the literal parts suggest.

Here, the compound meaning is not just something under a heel in a vague sense, but specifically a heel protector / heel cap.

Yes, in a normal sentence like this, the articles are expected:

Il sottotacco protegge il tacco.

Leaving them out would sound unnatural in standard Italian:

• Sottotacco protegge tacco is not correct standard usage.

Italian uses articles more regularly than English, especially with countable nouns in general statements and ordinary descriptions.