Els ous que vull són al prestatge del supermercat.

Here que is a relative pronoun. It links els ous to the extra information vull.

So:

• els ous = the eggs
• que vull = that I want

Literally, els ous que vull means the eggs that I want.

In Catalan, que is very common for that / which / who in relative clauses, and unlike English, Catalan does not usually drop it here. So English can say:

• the eggs I want

but Catalan normally says:

• els ous que vull

Vull is the 1st person singular present tense of voler, meaning to want.

So:

• voler = to want
• vull = I want

Examples:

• Vull pa. = I want bread.
• Vull aquests ous. = I want these eggs.

In your sentence, que vull means that I want.

Because the subject is plural:

• l’ou = the egg
• els ous = the eggs

So the verb must agree with that plural subject:

• és = is for singular
• són = are for plural

Compare:

• L’ou que vull és al prestatge. = The egg that I want is on the shelf.
• Els ous que vull són al prestatge. = The eggs that I want are on the shelf.

This is a very common learner question because English uses just to be, while Catalan has ser and estar.

In this sentence, són comes from ser. With location, Catalan often uses ser for a neutral statement of where something is, especially in general identification-type statements or straightforward location.

So:

• Els ous que vull són al prestatge = The eggs I want are on the shelf

In many contexts, especially in everyday speech, you may also hear estan for location, but són is perfectly normal here.

A useful beginner idea is:

• ser: identification, classification, and often neutral location
• estar: state, condition, or sometimes a more temporary/placed sense

The exact choice can depend on dialect and nuance, but this sentence is natural with són.

Els is the masculine plural definite article, meaning the.

So:

• els ous = the eggs

Catalan uses articles very regularly. In this sentence, we are talking about specific eggs: the ones the speaker wants.

If you said just ous, it would sound more like eggs in a general sense, not the eggs.

Because al is the normal contraction of:

• a + el = al

So:

• al prestatge = on/to the shelf

Catalan usually contracts these two words when they come together.

Other common contractions:

• de + el = del
• per + el = pel

That is why the sentence has:

• al prestatge
• del supermercat

not:

• a el prestatge
• de el supermercat

Del is a contraction of de + el, so:

• del supermercat = of the supermarket

The full phrase el prestatge del supermercat literally means:

• the shelf of the supermarket

In natural English, we would usually say:

• the shelf in the supermarket
• or the supermarket shelf

Catalan often uses de + noun where English may prefer a different structure.

Catalan word order here is very similar to English:

• Els ous = The eggs
• que vull = that I want
• són al prestatge del supermercat = are on the shelf of the supermarket

So the structure is:

noun + relative clause + verb + location

This is just like English:

• The eggs that I want are on the shelf.

You do not move que vull to the end. It stays right after the noun it describes: els ous.

Ou is masculine singular:

• l’ou = the egg

Its plural is ous:

• els ous = the eggs

So the article changes like this:

• singular masculine: el / l’
• plural masculine: els

Because ou begins with a vowel, singular el becomes l’:

• l’ou

But in the plural, you use:

• els ous

A helpful approximate pronunciation is:

• Els ous ≈ elz ows

A few useful notes:

• els is often pronounced with a z sound at the end before a vowel: elz
• ous sounds roughly like ows in English, but with a more open vowel

So together, it flows smoothly as elz-ows.

This linking between words is very normal in Catalan pronunciation.

Usually, yes. Prestatge normally means shelf.

So:

• al prestatge = on the shelf

Depending on context, it can also refer to a shelf as part of a shelving unit, but shelf is the standard translation and is exactly right here.

Normally, no. In English, both are possible:

• the eggs that I want
• the eggs I want

But in Catalan, you normally keep que:

• els ous que vull

Leaving it out would sound ungrammatical or very unnatural in standard Catalan. So for learners, it is safest to think:

• English may omit that
• Catalan usually keeps que