Learn Hardcore Portuguese (Portugal): A Ana criou um segundo perfil só para seguir páginas de ciência. - Ana created a second profile just to follow science pages.

In Portugal, using the article with names is normal and very frequent, especially in spoken language and informal writing.
In more formal or written contexts (news headlines, official documents, very formal speech), you may see the name without the article: Ana criou um segundo perfil…
In Brazilian Portuguese, using the article before names is less common in standard speech (though it appears in some regions).

So both Ana criou um segundo perfil… and A Ana criou um segundo perfil… are possible, but the version with A sounds very natural and colloquial in European Portuguese.

What tense is criou, and why is that form used here?

Criou is the 3rd person singular of the past simple (pretérito perfeito) of the verb criar (to create).

criar → ele/ela criou = he/she created

This tense is used to talk about a completed action in the past. In this sentence:

A Ana criou um segundo perfil…
= Ana created a second profile… (a finished action)

Other forms you might see, and what they mean:

Ana criava um segundo perfil… — Ana used to create / was creating a second profile… (imperfect, ongoing or habitual, not just a single completed event)
Ana tem criado perfis… — Ana has been creating profiles… (present perfect; less likely here)

So criou is the natural choice for a single, finished action in the past.

Why is it um segundo perfil? Could I say outro perfil instead, and is there a difference?

Both are possible, but they are not exactly the same:

um segundo perfil = a second profile
→ Explicitly tells you it is profile number 2, following the first one.
outro perfil = another profile
→ Just says it’s an additional profile; it doesn’t insist on the idea of “second in a sequence”.

In context:

If Ana has one profile, then creates one more, both um segundo perfil and outro perfil fit, but segundo highlights the order (first, second).
If Ana already has several profiles and makes yet another one, outro perfil would sound more natural, because it doesn’t limit the number to two.

So um segundo perfil subtly emphasizes “now she has two profiles”.

Why is segundo placed before perfil? Could I say perfil segundo?

In Portuguese, numeral adjectives (like primeiro, segundo, terceiro, dois, etc.) normally come before the noun:

um segundo perfil
a primeira página
os dois perfis

Perfil segundo is not natural here and would sound wrong in modern Portuguese.

So the normal word order is:

[article] + [numeral] + [noun]
um segundo perfil

Do I need the article um in um segundo perfil? Could I just say A Ana criou segundo perfil?

You need the article here. In natural Portuguese, you say:

A Ana criou um segundo perfil.

Omitting um in this type of sentence:

A Ana criou segundo perfil.

sounds very unnatural and ungrammatical in modern European Portuguese.

So keep the article:

um segundo perfil = a second profile

What exactly does só mean here, and how does it differ from apenas or somente?

Here só means “only / just”:

só para seguir páginas de ciência
= just / only to follow science pages

In European Portuguese:

só is very common and informal-neutral.
apenas is a bit more formal or written, but still common.
somente is used, but sounds a bit more formal or old-fashioned in Portugal (it’s more usual in Brazil).

You could say:

…um segundo perfil só para seguir páginas de ciência. (most natural)
…um segundo perfil apenas para seguir páginas de ciência. (slightly more formal)
…um segundo perfil somente para seguir páginas de ciência. (correct, more formal or Brazilian-flavoured)

All three mean essentially the same; só is the most everyday choice.

Why is só placed before para and not before seguir? Could I say para só seguir páginas de ciência?

Both are possible, with a slight nuance.

só para seguir páginas de ciência
- The whole purpose is limited: just to follow science pages and not for other purposes.
para só seguir páginas de ciência (less common, but possible)
- Emphasizes what she follows: in order to follow only science pages (and not other kinds of pages).

In practice:

The original só para seguir páginas de ciência is the most natural way to express “she created it just for this purpose”.
para só seguir is grammatically fine and subtly shifts the focus onto “only science pages”, but many speakers will still prefer the original order.

Why is para used before seguir? Is para + infinitive the normal way to express “in order to do something”?

Yes. In Portuguese, para + infinitive is the standard way to express purpose (“in order to / to do something”):

Um perfil para seguir páginas de ciência.
Estudo para passar no exame. = I study (in order) to pass the exam.

So:

só para seguir páginas de ciência
= just (in order) to follow science pages

Here seguir is the infinitive (to follow), and para + infinitive answers the question “Why did she create the profile?”.

Why do we use seguir without a preposition: seguir páginas and not seguir a páginas?

In this sense (“to follow” someone or something online), seguir is a transitive verb and takes a direct object without a preposition:

seguir páginas = to follow pages
seguir pessoas = to follow people
seguir um canal = to follow a channel

So:

para seguir páginas de ciência
is the normal structure: seguir + direct object.

Using seguir a páginas would be incorrect here.

Why is it páginas de ciência instead of páginas sobre ciência? Is there a difference?

Both de and sobre can work here, but they have slightly different flavours:

páginas de ciência
- Literally “pages of science”
- Very natural; suggests pages whose theme/content is science.
páginas sobre ciência
- Literally “pages about science”
- Slightly more explicit that the pages’ topic is science.

In everyday speech, páginas de ciência is shorter and sounds very natural, like livros de ciência (science books) or revistas de música (music magazines).

So the original páginas de ciência is perfectly idiomatic and maybe the most common phrasing.

Why is ciência in the singular? Could we say páginas de ciências as well?

Both are possible, but they’re not exactly the same:

páginas de ciência
- Think of “science” as a general field or concept.
- Like science pages / pages about science in general.
páginas de ciências
- Can suggest multiple branches of science or “(the) sciences” as separate disciplines (physics, biology, chemistry, etc.).
- You often see ciências in school subjects: Ciências Naturais (Natural Sciences).

In everyday talk about social media:

páginas de ciência is very common and sounds natural for “science pages”.
páginas de ciências is not wrong, but slightly less usual in this casual context.

How does agreement work in um segundo perfil and páginas de ciência?

Two types of agreement appear here:

Gender and number agreement with the noun:
- perfil is masculine singular, so:
  - um (masc. sing.)
  - segundo (masc. sing.) → um segundo perfil
- páginas is feminine plural, so:
  - as páginas (if you use the article)
  - any adjectives would also be feminine plural.
No change needed for ciência after de:
- de ciência — here ciência stays in the singular; it just names the type of pages.
- Only páginas would take plural marking.

So you match the article and the numeral/adjective to the main noun (perfil, páginas), not to the word after de.

How would the pronunciation of A Ana work in European Portuguese, since there are two a sounds together?

In European Portuguese, A Ana is usually pronounced as if it were one rhythm group, but you still have two vowels:

Roughly:

A Ana ≈ [ɐ ˈɐ.nɐ]
- First A is the article, often a short, reduced vowel [ɐ].
- Ana is stressed on the first syllable: A-na.

In normal speech, they flow together smoothly:

You do not insert a consonant between them in standard European Portuguese.
It does not become something like “Anã” or a single syllable; it’s just that the two a sounds come very close together.

So you might hear something like a quick “ɐˈɐnɐ”, but native speakers perceive it clearly as A Ana.