La abolladura demuestra el deterioro del bulto.

These are all nouns, and each has a grammatical gender:

• la abolladura → feminine
• el deterioro → masculine
• el bulto → masculine

In Spanish, gender is mostly a property of the noun itself, so it has to be learned together with the word.

A few useful patterns here:

• Nouns ending in -adura are often feminine: quemadura, cerradura, abolladura
• Nouns ending in -o are often masculine: deterioro, bulto

That is why the sentence uses la and el.

Abolladura is a noun meaning a dent or dented area, usually in a physical object such as metal, a car door, a can, or some other surface.

It comes from the verb abollar, meaning to dent.

Related forms:

• abollar = to dent
• abollado/a = dented
• abolladura = dent, dent mark

So la abolladura is the visible dent itself, not the action of denting.

Demuestra is the third-person singular present tense of demostrar.

Conjugation:

• yo demuestro
• tú demuestras
• él / ella / usted demuestra

In this sentence, the subject is la abolladura, which is singular, so the verb must also be singular:

• La abolladura demuestra...

A learner may also notice the stem change:

• demostrar changes from o to ue in many present-tense forms
• so it becomes demuestra, not demostra

Because de + el contracts to del in Spanish.

So:

• de + el bulto → del bulto

This contraction is mandatory in normal Spanish, except when el is part of a proper name, such as de El Escorial.

So here:

• el deterioro del bulto = the deterioration of the lump/package/bulge

Yes, bulto is a fairly broad word. Depending on context, it can mean things like:

• a lump
• a bulge
• a swelling
• a package or bundle
• a vaguely shaped mass or object

So this sentence is a bit context-dependent. Without context, bulto can sound ambiguous.

In Spain, bulto is common, but what it refers to depends on the situation:

• in medicine: a lump or swelling
• in everyday physical description: a bulge or protrusion
• in transport/logistics: a package or item of cargo

So the sentence is grammatically clear, but the exact image depends on what kind of bulto is being discussed.

Del bulto modifies el deterioro.

The structure is:

• La abolladura = the subject
• demuestra = the verb
• el deterioro del bulto = the direct object

More literally:

• The dent shows the deterioration of the lump/bulge/package

So del bulto tells you what is deteriorating.

It does not mean that the dent belongs to the lump directly; grammatically, it is the deterioro that is linked to bulto.

Yes, in many contexts you could.

• mostrar = to show
• demostrar = to demonstrate, prove, clearly show

Demuestra often sounds a bit stronger or more formal than muestra. It can suggest that the dent is clear evidence of the deterioration.

So:

• La abolladura muestra el deterioro del bulto = more neutral
• La abolladura demuestra el deterioro del bulto = stronger, more emphatic, slightly more formal

Both are possible, though the best choice depends on tone and context.

The given order is the most neutral:

• La abolladura demuestra el deterioro del bulto.

Spanish does allow some flexibility, but changing the order changes the emphasis.

For example:

• El deterioro del bulto lo demuestra la abolladura.
  This gives more emphasis to el deterioro del bulto.

• La abolladura, del bulto, demuestra el deterioro.
  This sounds unnatural in normal usage.

For learners, the original order is the safest and most standard: subject + verb + object.

Spanish often uses the simple present to state a fact, observation, or general description.

So:

• La abolladura demuestra... = The dent shows / demonstrates...

This does not necessarily mean it is happening right now as an action in progress. It means that, at present, the dent functions as evidence.

If you used a progressive form such as está demostrando, it would usually sound less natural here, because demostrar in this kind of sentence is more about a general state or interpretation than an ongoing action.

It is grammatically correct, but it sounds somewhat formal or technical, especially because of demuestra and deterioro together.

A more everyday sentence might depend on context. For example:

• La abolladura muestra que el bulto está deteriorado.
• La abolladura indica el deterioro del bulto.

The original sentence is fine, but it sounds like something from a report, inspection, description, or analysis rather than casual conversation.

Good question. These words overlap, but they are not identical:

• deterioro = deterioration, worsening condition, decline in state
• daño = damage
• desgaste = wear, wear and tear
• rotura = break, breakage

So deterioro focuses on the object being in a worse condition than before, often gradually or generally.

Examples:

• deterioro → the overall worsening
• daño → the specific damage
• desgaste → damage through use/friction over time

In your sentence, deterioro suggests that the dent is evidence of the object’s worsening condition, not just one isolated instance of damage.