Le vendeur explique qu’il y a une autre réduction à la caisse.

It means that there is.

• que = that
• il y a = there is / there are

So Le vendeur explique qu’il y a... means The salesperson explains that there is...

This is a very common structure in French after verbs like dire, penser, croire, expliquer, and savoir.

Because que becomes qu’ before a vowel sound.

French usually avoids saying two vowel sounds separately when a word like que comes before a word beginning with a vowel, such as il. So:

• que il → qu’il

This is called elision.

You will see the same thing in many other places:

• je ai → j’ai
• le ami → l’ami
• si il → s’il

Il y a is a fixed French expression meaning there is or there are.

Literally, its parts are:

• il = it/he
• y = there
• a = has

But you should not translate it word for word. As a whole, il y a simply means:

• there is for singular nouns
• there are for plural nouns

Examples:

• Il y a une réduction. = There is a discount.
• Il y a des réductions. = There are discounts.

In your sentence, il y a une autre réduction means there is another discount.

Because autre normally comes before the noun in French.

So:

• une autre réduction = another discount

This word order is standard. Putting autre after the noun would sound unnatural here.

French adjective position is something learners often have to memorize, because some adjectives come before the noun and some come after it. Autre is one of the ones that usually comes before.

Because réduction is a feminine noun.

So the article must be feminine:

• une réduction
• une autre réduction

If the noun were masculine, you would use un autre:

• un autre magasin = another store

So the form of the article changes to match the gender of the noun.

In a shop context, à la caisse means at the checkout, at the register, or at the cash desk.

Here, la caisse is not just a generic box. In stores, it usually refers to the place where you pay.

So une autre réduction à la caisse means there is an extra discount applied or available when you get to the checkout.

Because à is used for being at a place or point of service, while dans would mean inside something.

Compare:

• à la caisse = at the checkout
• dans la caisse = inside the cash register / inside the box

In this sentence, the idea is location or point of payment, so à la caisse is the natural choice.

Both are possible in French, but they do slightly different things.

• Le vendeur = the salesperson
• Un vendeur = a salesperson

Le vendeur suggests a specific salesperson, or the salesperson already known from the context. French often uses the definite article when the speaker assumes the listener can identify the person or thing.

So this sentence probably refers to a particular salesperson in the situation.

Explique is the present indicative form of expliquer.

It can translate as either:

• explains
• is explaining

French present tense often covers both the simple present and the English present progressive, depending on context.

So:

• Le vendeur explique... can mean The salesperson explains...
• or The salesperson is explaining...

Because expliquer que normally introduces a statement presented as a fact or piece of information, so French uses the indicative.

That is why you get:

• Le vendeur explique qu’il y a une autre réduction...

The subjunctive is more likely after expressions of doubt, emotion, necessity, or uncertainty, not after a straightforward verb like expliquer in this kind of sentence.

Historically, y means there, and that helps explain the expression. But in modern French, il y a functions as a set phrase.

So while it is useful to know that y originally contributes the idea of there, learners should mostly memorize il y a as one unit meaning:

• there is
• there are

You usually do not need to analyze y separately every time you use the expression.

Yes, réduction is a very common word for discount or price reduction.

You may also see remise, which can also mean discount, especially in commercial or formal contexts. The difference is often small in everyday use, but:

• réduction is very common in shops and advertising
• remise can sound a bit more business-like or technical

So une autre réduction à la caisse is a very natural store-related phrase.

It is pronounced as a smooth connected group, roughly like kee-lya.

A learner-friendly breakdown is:

• qu’il ≈ keel
• y a ≈ ya

In normal speech, it flows together very quickly:

• qu’il y a → keel-ya

This is one reason learners may find it hard to hear at first. Native speakers often say it very fast.