Garanția comercială nu acoperă dauna ascunsă.

It follows the very common Romanian pattern:

subject + nu + verb + direct object

So here:

• Garanția comercială = the subject
• nu = not
• acoperă = covers
• dauna ascunsă = the direct object

A word-for-word breakdown is:

• garanția = the warranty
• comercială = commercial
• nu = not
• acoperă = covers
• dauna = the damage
• ascunsă = hidden

So structurally, it is very close to English, except that Romanian does not need a separate word like does in the negative.

Because Romanian usually puts the definite article at the end of the noun, not in front of it.

So:

• garanție = warranty
• garanția = the warranty

and

• daună = damage
• dauna = the damage

This is one of the biggest differences from English. Instead of saying the warranty, Romanian often says something more like warranty-the.

A few similar examples:

• carte → cartea = book → the book
• casă → casa = house → the house
• garanție → garanția = warranty → the warranty

Because in Romanian, adjectives often come after the noun.

So:

• garanția comercială = the commercial warranty
• dauna ascunsă = the hidden damage

This is very normal Romanian word order.

English usually prefers:

• commercial warranty
• hidden damage

Romanian often prefers:

• warranty commercial
• damage hidden

Romanian can sometimes put the adjective before the noun, but that is less neutral and often adds emphasis or a slightly different tone.

Because adjectives in Romanian must agree with the noun in gender and number.

Here:

• garanția is feminine singular
• dauna is also feminine singular

So the adjectives must also be feminine singular:

• comercială
• ascunsă

Compare:

• un produs comercial = a commercial product
  masculine singular
• o garanție comercială = a commercial warranty
  feminine singular

And:

• un defect ascuns = a hidden defect
  masculine singular
• o daună ascunsă = a hidden damage / hidden damage
  feminine singular

Acoperă is the 3rd person singular present tense of the verb a acoperi, meaning to cover.

So:

• eu acopăr = I cover
• tu acoperi = you cover
• el/ea acoperă = he/she/it covers

In this sentence, the subject is garanția comercială, which is singular, so Romanian uses the singular verb form:

• Garanția comercială acoperă... = The commercial warranty covers...

When negated:

• Garanția comercială nu acoperă... = The commercial warranty does not cover...

Romanian negates a verb by putting nu directly before it.

So:

• acoperă = covers
• nu acoperă = does not cover

Unlike English, Romanian does not need an extra helping verb like does.

Compare:

• English: does not cover
• Romanian: nu acoperă

This is very common:

• nu știu = I do not know
• nu merge = it does not work
• nu acoperă = it does not cover

Because dauna ascunsă is an inanimate direct object, and Romanian normally does not use pe with that.

The marker pe is mainly used with personal or animate direct objects, especially specific people.

For example:

• Văd casa. = I see the house.
  no pe
• Văd copilul. = I see the child.
  often pe copilul
• Îl văd pe profesor. = I see the teacher.

Since dauna means damage, which is inanimate, no pe is needed:

• nu acoperă dauna ascunsă

It is an adjective here, but it is related to the verb a ascunde, meaning to hide.

So:

• a ascunde = to hide
• ascuns / ascunsă = hidden

In this sentence, ascunsă functions as an adjective describing dauna.

Because dauna is feminine singular, we get:

• dauna ascunsă

You can think of it roughly like English hidden, which also comes from a verb idea.

The dictionary forms are:

• garanție = warranty
• comercial = commercial
• a acoperi = to cover
• daună = damage
• ascuns or the verb a ascunde = hidden / to hide

This is useful because Romanian words often appear in changed forms in real sentences:

• garanție → garanția
• daună → dauna
• comercial → comercială
• ascuns → ascunsă
• a acoperi → acoperă

The two main special letters here are:

• ț = like ts in cats
• ă = a short neutral vowel, similar to the a in sofa

So for example:

• garanția has ț, pronounced like ts
• comercială, acoperă, and ascunsă contain ă

If you are reading aloud, the sentence is roughly:

ga-ran-TSI-a co-mer-ci-A-lă nu a-co-PE-ră DAU-na as-CUN-să

That is only an approximation, but it helps with the main sounds.

Yes, but the meaning changes.

• dauna ascunsă = the hidden damage
• o daună ascunsă = a hidden damage / a hidden instance of damage

So the sentence would become:

• Garanția comercială nu acoperă o daună ascunsă.

That would mean the warranty does not cover a hidden damage case or any hidden damage in a more indefinite sense.

The original sentence uses the definite form, so it points to a specific damage or to a defined category being referred to as known information.