À la poissonnerie, Marie rencontre sa sœur, qui travaille au pressing juste à côté.

À la poissonnerie means at the fish shop / at the fishmonger’s.

French often uses à to mean at or in when talking about places:

• à la boulangerie = at the bakery
• à la pharmacie = at the pharmacy
• à la poissonnerie = at the fish shop

So here, À la poissonnerie sets the scene: this is where the action happens.

This is because the form of à + the changes depending on the gender and number of the noun:

• à + le → au
• à + la → à la
• à + l’ → à l’
• à + les → aux

So:

• la poissonnerie is feminine singular → à la poissonnerie
• le pressing is masculine singular → au pressing

Examples:

• au restaurant
• à la banque
• à l’école
• aux toilettes

Poissonnerie usually means a fish shop or fishmonger’s shop.

It is not necessarily the same as a large fish market. A poissonnerie is often just an individual store where fish is sold.

Related words:

• poisson = fish
• poissonnier / poissonnière = fishmonger

Rencontre is the third person singular present form of rencontrer:

• je rencontre
• tu rencontres
• il/elle rencontre

Since the subject is Marie, the sentence uses rencontre.

So:

• Marie rencontre sa sœur = Marie meets / runs into her sister

French often uses the present tense in simple statements just like English does.

It can mean both, depending on context.

In this sentence, Marie rencontre sa sœur most naturally means Marie meets/runs into her sister, not is introduced to her sister for the first time.

That matters because English meet can sometimes suggest a first meeting, but French rencontrer is often broader:

• J’ai rencontré Paul hier. = I met/saw/ran into Paul yesterday.
• Ils se sont rencontrés en 2018. = They met each other in 2018.

Here, since it is her sister, the meaning is clearly runs into / comes across.

French possessive adjectives agree with the thing possessed, not with the owner.

Since sœur is feminine, French uses:

• sa sœur = his/her sister

Compare:

• son frère = his/her brother
• sa sœur = his/her sister

So sa does not mean the owner is female. It only agrees with sœur.

In this sentence, because the subject is Marie, we understand sa sœur as her sister.

This is a relative clause describing sa sœur.

Breakdown:

• sa sœur = her sister
• qui travaille au pressing = who works at the dry cleaner’s

So: sa sœur, qui travaille au pressing juste à côté
= her sister, who works at the dry cleaner’s right next door

The word qui here means who, and it refers back to sœur.

Use qui when the relative pronoun is the subject of the verb that follows.

Here:

• qui travaille = who works

The sister is the one doing the action of working, so qui is the subject of travaille.

Compare:

• la sœur qui travaille = the sister who works
• la sœur que Marie voit = the sister that Marie sees

In the second example, que is the object of voit.

The comma shows that this is extra information about the sister, not information needed to identify which sister.

So:

• Marie rencontre sa sœur, qui travaille au pressing...
  = Marie meets her sister, and by the way, that sister works at the dry cleaner’s...

If there were no comma, it could suggest a more restrictive meaning, like the sister who works at the dry cleaner’s as opposed to another sister.

So the comma makes the clause more like a parenthetical remark.

In French, un pressing means a dry cleaner’s.

This is one of those words that looks English but is used differently in French. A native English speaker would not normally say a pressing for this meaning, but French does.

So:

• au pressing = at the dry cleaner’s

This is sometimes called a pseudo-Anglicism: a word borrowed from English-looking material but used in a specifically French way.

Juste à côté means right next to it, just next door, or immediately nearby.

• à côté = next to / nearby
• juste à côté = right next to / just beside

In this sentence, it means the dry cleaner’s is very close to the fish shop.

Examples:

• La banque est à côté. = The bank is next door / nearby.
• Le café est juste à côté. = The café is right next door.

You can break it into three parts:

1. À la poissonnerie
   = At the fish shop

2. Marie rencontre sa sœur
   = Marie meets/runs into her sister

3. qui travaille au pressing juste à côté
   = who works at the dry cleaner’s right next door

So the sentence is:

At the fish shop, Marie runs into her sister, who works at the dry cleaner’s right next door.

This is a very common French structure:

• place first
• main clause
• relative clause for extra detail

Sœur can be tricky because of œ.

It is pronounced roughly like:

• sur in some accents of English is not quite right
• a better approximation is something like suhr, but with rounded lips

The important point is that it is one syllable:

• sœur

Also:

• œ is a special vowel combination often heard in words like cœur and sœur

If you are learning pronunciation, it helps to hear native audio for this word, because English does not have an exact equivalent.

In this sentence, juste à côté most naturally describes the pressing.

So the meaning is:

• the dry cleaner’s that is right next door

The structure strongly suggests: qui travaille [au pressing] [juste à côté]

That is, the sister works at a dry cleaner’s located nearby.

It would be much less natural to understand it as describing Marie or the sister’s physical position at that exact moment.