La bibliothécaire du quartier connaît bien le libraire de la rue voisine.

No. Libraire is a classic false friend for English speakers.

• un/une libraire = bookseller, or bookshop owner/worker
• un bibliothécaire / une bibliothécaire = librarian

So in this sentence:

• la bibliothécaire = the librarian
• le libraire = the bookseller

This is one of the most important vocabulary points in the sentence.

The articles show grammatical gender:

• la bibliothécaire = a female librarian
• le libraire = a male bookseller

A few useful notes:

• bibliothécaire can refer to either a man or a woman; the article tells you which.
  • le bibliothécaire = male librarian
  • la bibliothécaire = female librarian
• libraire works the same way:
  • le libraire = male bookseller
  • la libraire = female bookseller

So the sentence specifically describes a female librarian and a male bookseller.

Because de + le contracts to du, but de + la does not contract.

• de + le quartier → du quartier
• de + la rue voisine → de la rue voisine

This is a very common French pattern:

• du = de + le
• des = de + les
• but de la stays de la
• and de l’ stays de l’

So:

• la bibliothécaire du quartier = the librarian of/from the neighborhood
• le libraire de la rue voisine = the bookseller on/from the neighboring street

Here, du quartier does not mean literal ownership. It means something like the neighborhood librarian or the librarian from the neighborhood / in the neighborhood.

French often uses de where English might use:

• of
• from
• in
• or a noun used as an adjective

So la bibliothécaire du quartier is best understood as:

• the librarian who belongs to that neighborhood context
• the local neighborhood librarian

It is a natural French way to identify someone by place.

Because French uses connaître for being familiar with people, places, or things, and savoir for facts, information, or how to do something.

Here the librarian knows a person, le libraire, so French uses connaître.

Compare:

• Je connais ce libraire. = I know this bookseller.
• Je sais son adresse. = I know his address.
• Je sais nager. = I know how to swim.

So connaît bien le libraire means knows the bookseller well.

Here bien means well.

So:

• connaît bien = knows well

It tells us that the librarian is not just acquainted with the bookseller, but knows him fairly well.

In French, adverbs like bien often come right after the verb:

• Elle connaît bien ce libraire.
• Il parle bien français.

So the placement in the sentence is completely normal.

Voisine is an adjective modifying rue.

It is feminine because rue is feminine:

• la rue
• therefore voisine rather than voisin

So:

• la rue voisine = the neighboring street / the nearby street

As for position, many French adjectives come after the noun, and voisin / voisine commonly does in this meaning.

Compare:

• la rue voisine = the neighboring street
• le quartier voisin = the neighboring neighborhood

So the adjective agrees with the noun in gender and number.

It follows a very standard French pattern:

Subject + verb + adverb + object

More specifically:

• La bibliothécaire du quartier = subject noun phrase
• connaît = verb
• bien = adverb
• le libraire de la rue voisine = object noun phrase

You can think of it like this:

• [The neighborhood librarian] [knows well] [the bookseller from the neighboring street].

This is a useful sentence because it shows how French packs extra information into noun phrases with de.

Connaît is pronounced roughly like ko-NAY.

A few details:

• the t at the end is silent
• the ai sound here is like é / è depending on accent, but for learners NAY is a good guide
• the circumflex î does not mean you pronounce the i separately; it is still one syllable in the second part of the word

So:

• connaît ≈ ko-NAY

This is the il / elle form of connaître:

• je connais
• tu connais
• il/elle connaît

A careful pronunciation would be approximately:

la bee-blee-oh-tay-KAIR du kar-TYAY kon-NAY byan luh lee-BRER duh la roo vwah-ZEEN

A few helpful pronunciation notes:

• bibliothécaire: the stress in French is not as strong as in English, but the end of the phrase tends to sound more prominent
• quartier sounds roughly like kar-tyay
• connaît ends with a silent t
• libraire sounds roughly like lee-brer
• voisine sounds roughly like vwah-zeen

Also, French rhythm is smooth and linked, so the sentence should flow rather than sound heavily separated word by word.

French uses articles more regularly than English does. In this sentence, each main noun takes an article:

• la bibliothécaire
• le quartier
• le libraire
• la rue voisine

English sometimes does something similar, but French is less likely to omit the article in ordinary noun phrases.

So even though English might sometimes say something compact like the neighborhood librarian, French naturally says la bibliothécaire du quartier.

Because French often expresses that kind of idea with de + place instead of using a separate adjective.

So rather than saying something literally like the local librarian, French can say:

• la bibliothécaire du quartier

This often sounds more concrete and idiomatic. It identifies the person by their connection to a place.

You will see this pattern a lot:

• le boulanger du village = the village baker
• la pharmacie du centre-ville = the pharmacy in downtown
• le médecin du quartier = the neighborhood doctor

For this meaning, la rue voisine is the natural choice.

• voisin / voisine means neighboring, nearby, next-door
• prochain / prochaine usually means next in time or sequence, and is not normally used for a nearby street in this way

So:

• la rue voisine = the neighboring street
• la semaine prochaine = next week

A native English speaker might want to translate next street directly, but in French la rue voisine is usually the better expression here.