Je vais passer à la boulangerie avant de rentrer à la maison.

In this sentence, aller + infinitive forms the near future, so je vais passer means I’m going to stop by or I’m going to go by.

• je vais = I am going
• passer = to pass / to stop by / to drop in, depending on context

With a place after it, passer à + place often means to stop by that place briefly.

So:

• Je vais passer à la boulangerie = I’m going to stop by the bakery

It does not mean I go to pass in normal English. The whole expression works together as a future action.

Here, passer à la boulangerie means to stop by the bakery or to pop into the bakery.

The verb passer has many meanings in French, including:

• to pass
• to spend (time)
• to take (an exam, a call, etc.)
• to stop by

In this sentence, the context makes it clear that it means stop by briefly.

Examples:

• Je passe au supermarché. = I’m stopping by the supermarket.
• Je passerai chez toi ce soir. = I’ll stop by your place tonight.

French often uses à with shops and public places where English might use to, at, or even no preposition in translation.

So:

• passer à la boulangerie = stop by the bakery
• aller à la boulangerie = go to the bakery

Using dans la boulangerie would focus more on being inside the bakery physically. That is possible in some contexts, but it is not the normal choice after passer here.

So à la boulangerie is the natural way to say at/to the bakery in this sentence.

After avant, when the next verb stays in the infinitive, French uses de:

• avant de + infinitive

So:

• avant de rentrer = before going back / before returning

This is a standard grammar pattern:

• avant de partir = before leaving
• avant de manger = before eating
• avant de dormir = before sleeping

You cannot normally say avant rentrer.

Rentrer means to return, to go back, or to come home/back, depending on context.

So:

• rentrer à la maison = to go home / return home

French often uses rentrer when the idea is going back to where you belong or started from, especially home.

Compare:

• aller à la maison = to go to the house/home
• rentrer à la maison = to go back home

In this sentence, the person is stopping at the bakery before returning home, so rentrer fits better.

English can say home with no article or preposition phrase, but French usually uses a full expression:

• à la maison = at home / home
• rentrer à la maison = to go home
• être à la maison = to be at home

French does not usually say rentrer maison.

So even though English uses a single word, French needs the prepositional phrase à la maison.

Yes. You could say:

• Je passerai à la boulangerie avant de rentrer à la maison.

That means I’ll stop by the bakery before going home.

The difference is mainly tone:

• Je vais passer... = near future, often more conversational, more immediate
• Je passerai... = simple future, also correct, sometimes a bit more neutral or formal

Both are very natural.

Not exactly.

• aller à la boulangerie = to go to the bakery
• passer à la boulangerie = to stop by the bakery

Passer suggests a brief visit, often on the way somewhere else. In this sentence, that fits perfectly because the speaker will stop there before going home.

So passer adds the idea of dropping in rather than simply going.

Because both expressions use the preposition à before a feminine singular noun with the article la:

• à + la boulangerie = à la boulangerie
• à + la maison = à la maison

This is just the normal combination of the preposition à with the feminine article la.

For comparison:

• à + le becomes au
• à + les becomes aux

Examples:

• au supermarché
• aux États-Unis

But with la, there is no contraction:

• à la gare
• à la banque
• à la maison

A natural pronunciation is roughly:

Je vais passer à la boulangerie avant de rentrer à la maison.
→ zhuh vay pah-say ah lah boo-lahn-zhuh-ree ah-vahn duh rahn-tray ah lah meh-zohn

A few useful notes:

• Je is often very light: zhuh
• vais sounds like vay
• boulangerie has the zh sound in the middle
• avant has a nasal vowel: ah-vahn
• rentrer also has a nasal vowel at the start: rahn-tray

In normal speech, French rhythm is smooth and connected, but there is no major special trick in this sentence beyond the usual flow.

Yes, depending on the exact meaning.

Possible alternatives:

• Je vais aller à la boulangerie avant de rentrer à la maison.
  = I’m going to go to the bakery before going home.
  More neutral, less like a quick stop.

• Je vais m’arrêter à la boulangerie avant de rentrer à la maison.
  = I’m going to stop at the bakery before going home.
  Very close in meaning.

• Je vais faire un tour à la boulangerie...
  = I’m going to make a quick trip to the bakery...
  More informal and slightly different in tone.

But passer à la boulangerie is very natural for a quick stop on the way somewhere else.