No me fío de esa página web, porque no explica quién escribe la información.

Because the verb here is fiarse de, which means to trust or to rely on something/someone.

So:

• fiar on its own can mean things like to entrust, to sell on credit, or to trust in some contexts
• but fiarse de is the very common everyday pattern for to trust

That is why Spanish uses the pronoun:

• yo me fío
• tú te fías
• él/ella se fía

In this sentence, No me fío de esa página web literally looks like I do not trust myself of that website, but the natural meaning is simply I don’t trust that website.

So the me is not optional here: it is part of the verb structure fiarse de.

Because fiarse normally goes with de.

So you say:

• Me fío de ti = I trust you
• No me fío de esa persona = I don’t trust that person
• No me fío de esa página web = I don’t trust that website

This is just something you need to learn with the verb, like learning that English says depend on rather than just depend in some contexts.

Here fío is the first person singular present form:

• yo me fío = I trust
• yo no me fío = I don’t trust

The accent mark in fío shows that the vowels are pronounced separately: FI-o, not as one syllable.

The same happens in other forms of this verb:

• me fío
• te fías
• se fía

So the accent is there for pronunciation and stress.

Esa means that.

Spanish demonstratives change to match the noun in gender and number:

• este / esta = this
• ese / esa = that
• aquel / aquella = that over there

Here, página is feminine singular, so we use esa.

So:

• esa página web = that website

Because the main noun is página, and página is feminine:

• la página
• una página
• esa página

Even though web is also used in Spanish, the gender here is determined by página, not by web.

So:

• esa página web
• la página web

Because porque (one word, no accent) means because.

This sentence gives a reason:

• No me fío de esa página web, porque...
• I don’t trust that website, because...

Compare:

• porque = because
• por qué = why

Examples:

• No voy porque estoy cansado. = I’m not going because I’m tired.
• ¿Por qué no vas? = Why aren’t you going?

So here porque is correct because it introduces the reason.

Because it is an indirect question.

The sentence says:

• no explica quién escribe la información

That means something like:

• it doesn’t explain who writes the information

Even though there are no question marks, the word quién still introduces a question idea: who writes it?

That is why Spanish uses the accented form:

• quién = who? / whoever in question-like uses

Compare:

• No sé quién es. = I don’t know who he/she is.
• La persona que escribe... = the person who writes...

So quién has an accent because it is interrogative, even inside a larger statement.

Because the meaning is who writes the information, not that writes the information.

Spanish uses:

• quién = who
• que = that / which / who in relative clauses

Compare:

• No explica quién escribe la información. = It doesn’t explain who writes the information.
• La persona que escribe la información... = The person who writes the information...

So quién is used because the identity of the writer is unknown and being asked about indirectly.

Both are possible.

• explica quién escribe la información
• explica quién la escribe

The original sentence repeats la información, which makes it very clear and natural.

If you use la, it refers back to la información:

• No explica quién la escribe = It doesn’t explain who writes it

Spanish often allows either repetition of the noun or replacement with a pronoun, depending on style and clarity.

Because Spanish often uses the definite article with abstract or general nouns where English may not.

So Spanish commonly says:

• la información = the information
• la música = music
• la vida = life

In this sentence, la información refers to the information on that website, so the article sounds natural.

English often drops the article, but Spanish keeps it more often.

Yes, that is also correct.

• No me fío de esa página web
• No confío en esa página web

Both can mean I don’t trust that website.

A small difference in feel:

• fiarse de is very common and conversational
• confiar en can sound a little more neutral or formal depending on context

Also notice the different prepositions:

• fiarse de
• confiar en

So you must say:

• me fío de...
• confío en...

not me fío en or confío de in this meaning.

Because the subject is esa página web, which is singular.

So:

• esa página web explica = that website explains
• esas páginas web explican = those websites explain

Even though a website contains many pages or many people may be behind it, grammatically the subject here is one singular noun: página web.

The structure is:

• No me fío de esa página web
• porque no explica quién escribe la información

Broken down:

1. No = negation
2. me fío de esa página web = I trust that website
3. porque = because
4. no explica = it does not explain
5. quién escribe la información = who writes the information

Spanish word order here is very natural and close to English, but notice two important differences:

• the object pronoun comes before the verb: me fío
• the verb pattern is fiarse de

So the sentence is very useful as a model:

• No me fío de X porque no explica Y.