Il lucido da scarpe protegge il cuoio.

Da scarpe means for shoes, not from shoes.

So lucido da scarpe is a fixed expression meaning shoe polish.
Literally, you can think of it as polish for shoes.

In Italian, da + noun is often used to show purpose or intended use:

• spazzolino da denti = toothbrush
• occhiali da sole = sunglasses
• scarpe da tennis = tennis shoes

So lucido da scarpe follows a very common pattern.

Italian uses definite articles more often than English.

So even where English might say:

• Shoe polish protects leather

Italian often says:

• Il lucido da scarpe protegge il cuoio

This is normal when talking about something in a general sense, especially with categories, materials, or things as a class.

A learner should not try to match article use word-for-word with English. Italian often sounds more natural with the article here.

Yes, lucido can be an adjective meaning shiny, glossy, or sometimes clear-headed, depending on context.

But in this sentence, il lucido is a noun, and it means polish.

So:

• lucido as an adjective: una superficie lucida = a shiny surface
• il lucido da scarpe as a noun phrase: shoe polish

This is a good example of how a word can have different roles depending on context.

Protegge is the third person singular present tense of proteggere, meaning to protect.

The subject is il lucido da scarpe, which is singular, so the verb must also be singular:

• il lucido da scarpe protegge = shoe polish protects

A few useful forms of proteggere:

• io proteggo = I protect
• tu proteggi = you protect
• lui/lei protegge = he/she/it protects
• noi proteggiamo = we protect
• voi proteggete = you all protect
• loro proteggono = they protect

Because Italian does not usually need a subject pronoun when the subject is already stated.

Here, the subject is explicitly given:

• Il lucido da scarpe protegge il cuoio

So there is no need to add esso or another pronoun. In fact, that would usually sound unnatural.

Italian commonly leaves out subject pronouns unless they are needed for emphasis or clarity.

Cuoio means leather, especially leather as a material, often fairly thick or treated.

Pelle can also refer to skin or hide, and in some contexts it can mean leather too, but it is broader.

A simple way to think about it:

• pelle = skin / hide / sometimes leather
• cuoio = leather as a worked material

So in a sentence about shoe polish, cuoio is a very natural choice.

Cuoio can be tricky for English speakers.

It is pronounced roughly like KWOH-yoh.

A helpful breakdown is:

• cuo-io

The cuo part sounds like kwo, and then io sounds like yo.
Try to say it smoothly as two flowing parts, not as many separate syllables.

Also:

• c before u is a hard k sound
• so cuoio does not sound like English chew

Yes, but the original order is the most neutral and natural:

• Il lucido da scarpe protegge il cuoio.

Italian word order is often flexible, but changing it usually affects emphasis.

For example, putting il cuoio earlier could sound more marked or literary, depending on context. For a basic statement, the standard subject + verb + object order is best.

So for learners, this sentence is a good model to follow as it is.

Because the phrase means polish for shoes in general, not for one specific shoe.

Italian often uses the plural in this kind of fixed expression when talking about the usual purpose of an object:

• lucido da scarpe = polish for shoes
• spazzola da capelli = hairbrush
• sala da pranzo = dining room

It is describing what the item is used for, not referring to a particular pair of shoes.

Yes, the sentence is grammatically correct and natural.

That said, in everyday speech, people might also say similar things depending on context, such as:

• Il lucido protegge il cuoio.
• Il lucido da scarpe aiuta a proteggere il cuoio.

But your sentence is a perfectly good standard example, especially for learning vocabulary and structure.