Al congelador no hi cap més menjar, així que demà comprarem menys carn.

Here Al congelador means in the freezer.

• al = a + el
• In Catalan, a is often used for location where English would use in or at

So even though a can sometimes suggest movement in English, here it is simply locative: in the freezer.

Hi is a locative pronoun, roughly meaning there or in it.

In this sentence, it refers back to al congelador. So:

• Al congelador no hi cap més menjar
• literally: In the freezer, no more food fits there

More natural English would be:

• There isn’t room for more food in the freezer
• No more food fits in the freezer

Catalan often uses hi even when the place has already been mentioned.

No. Here cap is a verb form, not the determiner cap meaning any.

It comes from the verb cabre, which means to fit.

So:

• cap = fits
• no hi cap més menjar = no more food fits in there

This is different from a sentence like:

• No hi ha cap problema = There isn’t any problem

In that example, cap means any. In your sentence, it is the verb.

Because in this sentence cap is the verb fits, not a negative word.

So the negation must be expressed with no:

• hi cap = it fits there
• no hi cap = it doesn’t fit there

If you confuse cap here with the determiner any, the sentence becomes hard to understand. The key is: this cap is verbal.

Because menjar here means food, which is a mass noun and grammatically singular.

So Catalan treats més menjar as singular:

• cap més menjar = more food fits

Compare:

• No hi cap més menjar = No more food fits
• No hi caben més plats = No more plates fit

With plats (plates), the verb is plural: caben.

Because més and menys can go directly before a noun.

So these are normal:

• més menjar = more food
• menys carn = less meat

You do not need de here.

You do use de in other structures, such as:

• més de tres quilos = more than three kilos

But with a noun directly after més or menys, no de is needed.

Not exactly. It means there is no more room for food, not there is no more food available.

So the idea is:

• the freezer is full
• more food would not fit inside it

A natural English translation is:

• No more food fits in the freezer
• There isn’t room for more food in the freezer

Així que means so, therefore, or so that means in this kind of sentence.

It introduces a consequence:

• Al congelador no hi cap més menjar, així que demà comprarem menys carn.
• No more food fits in the freezer, so tomorrow we’ll buy less meat.

It is a very common connector in everyday Catalan.

Comprarem is the 1st person plural future of comprar:

• jo compraré
• tu compraràs
• ell/ella comprarà
• nosaltres comprarem

So demà comprarem means tomorrow we will buy.

Because the sentence talks about a future action, the future tense is very natural here.

In spoken Catalan, the present can sometimes be used for future meaning too, but comprarem is clear and standard.

Menys does not always need the second part of the comparison to be said explicitly.

Here it means something like:

• less meat than usual
• less meat than we would otherwise buy
• less meat because there isn’t enough space

The comparison is understood from the context.

So demà comprarem menys carn is perfectly natural even without saying exactly what it is being compared to.

In standard Catalan, that would sound wrong or at least incomplete.

With this kind of locative idea, hi is normally needed:

• Al congelador no hi cap més menjar ✔
• Al congelador no cap més menjar ✘

Even though al congelador is already present, Catalan still commonly keeps hi. This kind of doubling is very normal in Catalan grammar.