El barniz protege la veta de la madera.

Because barniz is a masculine noun in Spanish, so it takes the masculine article el.

• el barniz = the varnish
• un barniz = a varnish

The ending -iz does not tell you the gender by itself, so this is something you usually just learn with the noun.

Barniz means varnish, the protective coating put on wood and other surfaces.

In this sentence, it refers to the substance that covers the wood and helps protect its appearance.

Because protege is the conjugated form of the verb proteger.

• proteger = to protect
• protege = it protects / he protects / she protects

Here the subject is el barniz, which is third person singular, so the verb must also be third person singular:

• El barniz protege... = The varnish protects...

It is the present simple (also called the present indicative).

In a sentence like this, the present tense is often used for a general fact or a normal function:

• El barniz protege la veta de la madera.
  = Varnish protects the wood grain.

So it is not necessarily happening right now at this exact second; it can describe what varnish generally does.

Here veta means grain, specifically the natural lines and pattern in wood.

So la veta de la madera means the grain of the wood or the wood grain.

Be careful: veta can also have other meanings in other contexts, such as a vein in rock or mineral, but in this sentence it clearly refers to wood grain.

Because Spanish often expresses this idea with de:

• la veta de la madera = literally the grain of the wood

This is a very normal Spanish structure. English often uses a noun directly before another noun (wood grain), but Spanish usually prefers:

• noun + de + noun

So:

• la puerta de la casa = the house door / the door of the house
• el color del coche = the car’s colour
• la veta de la madera = the wood grain

Because both nouns are being treated as specific, identifiable things.

• la veta = the grain
• la madera = the wood

Spanish uses the definite article more often than English does. In English, you might simply say wood grain, but Spanish naturally says la veta de la madera.

So even where English sounds more general or compact, Spanish often still uses el / la / los / las.

No, that would not be correct.

Spanish normally needs the link de here:

• la veta de la madera = correct
• la veta madera = not natural / not correct in this meaning

English can stack nouns together more easily (wood grain, stone wall, car door), but Spanish usually cannot do that in the same way.

In standard Peninsular Spanish, protege is pronounced roughly like:

pro-TE-he

A few useful pronunciation points:

• the g before e sounds like a strong throaty sound, similar to the j in Spanish
• the stress falls on te: proTEge

So in Spain it is approximately pro-TE-khe / pro-TE-he, depending on how you describe the sound.

In Spain, barniz is pronounced roughly:

bar-NEETH

The final z in most of Spain is pronounced like the th in think.

So:

• barniz → bar-NEETH

This is a useful Spain-specific pronunciation point. In much of Latin America, that final z would sound more like an s.

The normal and most natural order is:

El barniz protege la veta de la madera.

That is:

• subject: El barniz
• verb: protege
• object: la veta de la madera

Spanish does allow some flexibility in word order, but in a basic statement like this, the standard order is best. Moving things around would usually sound marked, poetic, or unnatural unless there is a special emphasis.

Yes, Spanish often drops the subject pronoun, but here the subject is not a pronoun — it is the noun el barniz.

If you say only Protege la veta de la madera, that means:

• He/she/it protects the wood grain
• or it could even sound like a command in another context, depending on punctuation and situation

So if you want to clearly say that the varnish is what protects the grain, it is better to keep el barniz.

Yes, that is a reasonable English rendering, depending on context.

The Spanish literally points to the grain of the wood, but natural English could be:

• The varnish protects the wood grain.
• The varnish protects the grain of the wood.
• The varnish protects the grain in the wood.

The exact best translation depends on style, but the Spanish structure itself is straightforward: varnish is protecting the wood’s grain.