Learn Hardcore Portuguese (Portugal): A bibliotecária fala com as crianças com carinho. - The librarian speaks to the children gently.

Yes, it’s natural. The first com belongs to the verb phrase falar com alguém (to talk with/to someone). The second com introduces a manner phrase (com carinho = with affection/kindly). So it’s literally “speaks with the children with affection.”

Can I change the word order to avoid repeating com?

You can, but the original order is very natural. Acceptable options:

A bibliotecária fala com carinho com as crianças.
A bibliotecária fala com as crianças carinhosamente. The most common is to keep the person right after the verb: fala com as crianças…, then add manner info.

Could I use an adverb instead of com carinho?

Yes: carinhosamente. Example: A bibliotecária fala carinhosamente com as crianças. It sounds a bit more formal/literary than com carinho, which is very common in speech.

Why fala (simple present) and not a progressive like “is speaking”?

In European Portuguese, the simple present covers both habitual and current actions, like English “speaks” or “is speaking,” depending on context. If you need to stress an action happening right now, EP prefers está a falar: A bibliotecária está a falar com as crianças com carinho.

Why as crianças (feminine plural) even if the group could be mixed?

Because criança is grammatically feminine in Portuguese regardless of the child’s sex. So the plural is as crianças even for mixed groups.

Could I drop the article and say fala com crianças?

Yes, but it changes the meaning:

com as crianças = with the children (specific group or children in general as a class).
com crianças = with children (some children, non-specific). In European Portuguese, the definite article is often used for generic groups: as crianças = children (in general).

Why falar com and not falar a or falar para?

falar com = talk with/to (interactive or conversational).
falar a = speak to (more one-way/formal; used but less common in everyday speech for this context).
falar para is common in Brazil for “speak to,” but in Portugal it’s less common here and can sound directional rather than interactive. Your sentence is about a warm interaction, so falar com fits best.

If I use falar a, do I need a contraction like às crianças?

Yes. a + as contracts to às (with a grave accent): A bibliotecária fala às crianças com carinho. That’s correct Portuguese, but again, falar com is the more natural choice for a conversation.

Does com contract with articles (like “do/da/no/na”)?

Not in standard writing. You write com o, com a, com os, com as. There are special forms only with certain pronouns: comigo, contigo, connosco, convosco (EP spelling). Colloquial speech may slur com as to something like “c’as,” but you don’t write it that way.

Any pronunciation tips for this sentence in European Portuguese?

crianças: the ã is nasal; the final -s is like “sh” before a consonant.
com: the vowel is nasal (roughly “koh̃”).
carinho: nh = “ny” (like Spanish ñ).
bibliotecária: stress on -cá- (marked by á).
Single r between vowels (as in carinho, bibliotecária) is a light tap, not the guttural sound of initial r.

What do the accent marks and the ç tell me?

á in bibliotecária marks the stressed syllable and an open vowel.
ã in crianças marks nasalization.
ç (cedilha) in crianças makes the “s” sound before a/o/u.

Is bibliotecária feminine because of the ending? What’s the masculine?

Yes. bibliotecária is the feminine form; the masculine is bibliotecário. The article and adjectives must agree: A bibliotecária fala… / O bibliotecário fala…

Could I use a more informal word for “children” in Portugal?

Yes:

Informal: os miúdos (kids).
Depending on context: os meninos (often “boys,” but sometimes used for children in general, e.g., at school). Your sentence with an informal tone: A bibliotecária fala com os miúdos com carinho.

Do I need a subject pronoun (like Ela)?

No. Portuguese often drops subject pronouns when the subject is clear. Here, A bibliotecária is the subject, so adding Ela is unnecessary.