Les chaussures dans la vitrine sont en promotion.

Les means the, while des means some.

In Les chaussures dans la vitrine, the speaker is referring to a specific set of shoes: the shoes in the display window. The phrase dans la vitrine identifies which shoes we mean, so French naturally uses les.

If you said Des chaussures dans la vitrine sont en promotion, it would sound more like Some shoes in the window are on sale, which is possible, but less definite.

Because chaussures is plural: it means shoes.

French nouns usually add -s in the plural:

• la chaussure = the shoe
• les chaussures = the shoes

Even though the final -s is usually not pronounced, it still matters in writing and for grammar agreement.

Because the subject is plural: Les chaussures.

The verb être changes depending on the subject:

• la chaussure est = the shoe is
• les chaussures sont = the shoes are

So sont is the correct plural form of être here.

It means in the display window or in the shop window.

• dans = in / inside
• la vitrine = the display window, especially a store window showing products

So les chaussures dans la vitrine means the shoes in the window display.

Because vitrine is a feminine noun in French.

So you say:

• la vitrine = the display window

In French, every noun has grammatical gender, and the article has to match:

• le for masculine singular
• la for feminine singular
• les for plural

En promotion is a fixed expression meaning on sale, discounted, or being promoted in a special offer.

French often uses en in set phrases like this. You usually just learn être en promotion as a chunk.

Examples:

• Ce produit est en promotion. = This product is on sale.
• Les chaussures sont en promotion. = The shoes are on sale.

It does not literally match English word-for-word. A learner should remember the whole expression rather than trying to translate en by itself here.

Not exactly.

• en promotion means on special offer / discounted
• en soldes refers more specifically to official sale periods, especially seasonal sales

So a store might say:

• Ce pull est en promotion = This sweater is on promotion / discounted
• Les soldes commencent demain = The sales start tomorrow

In many everyday situations, en promotion is the safer general phrase for on sale.

French allows both structures, depending on what you want to emphasize.

This sentence:

• Les chaussures dans la vitrine sont en promotion.

focuses on the shoes in the window as the subject.

You could also say:

• Les chaussures sont en promotion dans la vitrine.

But that version can sound like the promotion is happening in the window, not necessarily that the shoes in the window are the specific shoes being described.

So Les chaussures dans la vitrine is a natural way to clearly identify which shoes are on sale.

Yes, several letters are silent, which is very common in French.

A rough pronunciation is: lay shoh-SYUR dahn la vee-TREEN sohn ahn pro-mo-see-ON

A few important points:

• The -s in les is usually silent, but it links in speech before a vowel.
• The -s in chaussures is silent.
• The -s in dans is silent.
• The -ent ending in sont is not pronounced; sont sounds roughly like son with a nasal vowel.
• The final -n in promotion is part of a nasal sound, not a fully pronounced English n.

There is also a liaison in:

• les chaussures → the s of les is pronounced like z before chaussures

So it sounds like: lez chaussures

Sometimes, but the meaning changes slightly.

• dans la vitrine = in the display window
• de la vitrine = of/from the display window

If you want to describe location, dans la vitrine is the clearest choice.

Les chaussures de la vitrine could mean the shoes from the display window, for example when distinguishing them from shoes somewhere else in the store. It is possible, but it is less directly about location.

Yes. A common alternative is:

Il y a des chaussures en promotion dans la vitrine.

That means: There are shoes on sale in the display window.

The difference is:

• Les chaussures dans la vitrine sont en promotion. = focuses on the shoes in the window
• Il y a des chaussures en promotion dans la vitrine. = introduces the existence of some shoes on sale in the window

So the original sentence is more definite, while the il y a version is more like presenting information.

Grammatically, it most naturally suggests the shoes in the window as a group are on sale.

Because it uses les chaussures dans la vitrine, it sounds like the shoes being referred to are the ones in the display window.

If you wanted to clearly say only some of them, French might use:

• Certaines chaussures dans la vitrine sont en promotion. = Some of the shoes in the window are on sale.
• Quelques chaussures dans la vitrine sont en promotion. = A few shoes in the window are on sale.

So the original sentence sounds more definite and broader than some shoes.

In other contexts, promotion can mean other things, such as:

• a promotion at work
• a graduating class
• a marketing campaign

But in the phrase être en promotion, especially in a shopping context, it clearly means to be on sale / discounted.

So in this sentence, a native speaker would understand it as a store-price meaning, not a job-related meaning.