La persona beneficiaria firma la declaración responsable.

Because beneficiaria is agreeing with persona, and persona is a feminine noun in Spanish.

• persona = person
• beneficiaria = beneficiary / entitled party

In Spanish, adjectives usually agree in gender and number with the noun they describe, so:

• la persona beneficiaria
• not la persona beneficiario

That said, in many contexts Spanish also uses el beneficiario / la beneficiaria as a noun by itself. This sentence just uses the more formal phrase la persona beneficiaria, which is very common in administrative and legal Spanish in Spain.

Not necessarily.

Even though persona is grammatically feminine, it can refer to any person, regardless of biological sex or gender. Because persona is feminine, the adjective also appears in the feminine form:

• la persona beneficiaria

So this is often just a grammatical choice, not a statement about the person being female.

Firma here is the third-person singular present indicative of firmar:

• firmar = to sign
• firma = he/she signs, you (formal) sign

So the sentence structure is:

• La persona beneficiaria = subject
• firma = verb
• la declaración responsable = direct object

Depending on context, it can be translated as:

• signs
• is signing
• sometimes even must sign in administrative instructions, depending on the broader text

Yes. Firma can also be a noun meaning signature or company/firm, depending on context.

For example:

• Necesito tu firma. = I need your signature.
• Es una firma internacional. = It is an international firm/company.

But in La persona beneficiaria firma la declaración responsable, it is clearly a verb, because it comes after the subject and before the object.

Spanish uses the definite article more often than English.

Here:

• La persona beneficiaria = the beneficiary person / the beneficiary
• la declaración responsable = the sworn/self-responsibility statement

The articles show that both are being treated as specific, identifiable things in context.

In formal or legal Spanish, this is very normal. English might sometimes drop an article where Spanish keeps it, but in this sentence both la forms are perfectly standard.

Because in Spanish, adjectives usually come after the noun.

So:

• declaración responsable = literally responsible declaration

That word order is the normal one in Spanish.

Also, declaración responsable is a fixed administrative/legal expression in Spain. It refers to a formal statement in which someone declares that they meet certain requirements or that the information provided is true.

So even if the literal wording feels strange in English, the Spanish phrase is standard official terminology.

Literally, responsable means responsible, but in this legal phrase it does not work exactly like normal everyday English responsible.

In Spain, declaración responsable is a set legal term. It usually means a formal declaration in which the person takes responsibility for the truth of what they state and for meeting the relevant conditions.

So this is better understood as an official legal label, not as a casual adjective.

Because la declaración responsable is a thing, not a person.

Spanish uses the personal a before specific human direct objects, for example:

• Veo a la profesora. = I see the teacher.

But here the object is a document:

• firma la declaración responsable

So there is no personal a.

Here it is functioning as an adjective modifying persona.

• persona = noun
• beneficiaria = adjective describing which person

So the phrase means something like the beneficiary person or more naturally the beneficiary.

However, beneficiaria can also be used as a noun on its own:

• La beneficiaria firma el documento. = The beneficiary signs the document.

Both are possible, but la persona beneficiaria sounds especially formal and administrative.

Because declaración is stressed on the last syllable: de-cla-ra-ción.

In Spanish, words ending in n, s, or a vowel are normally stressed on the second-to-last syllable unless there is a written accent. Since this word is stressed on the last syllable, it needs the accent mark:

• declaración

Without the accent, declaracion would not follow normal Spanish spelling rules.

Yes, very much so.

Expressions like:

• la persona beneficiaria
• declaración responsable

are typical of official documents, public administration, legal texts, and application forms in Spain.

In everyday conversation, a speaker might say something simpler depending on context, but in paperwork this style is completely normal.