El sac de dormir és a la tenda de campanya.

Catalan often uses noun + de + infinitive/noun where English uses a compound noun or an adjective.

• sac = bag
• de dormir = for sleeping / to sleep

So sac de dormir literally looks like bag for sleeping, but it is simply the normal way to say sleeping bag.

The same pattern appears in many Catalan expressions, so it is worth getting used to.

Catalan nouns have grammatical gender.

• el is the masculine singular definite article
• la is the feminine singular definite article

In this sentence:

• el sac because sac is masculine
• la tenda because tenda is feminine

This is grammatical gender, so it does not mean the objects are actually male or female. It is just part of how the language works, and you usually have to learn the gender with each noun.

The accent in és is important.

• és = is
• es = a different word, often a reflexive pronoun like himself/herself/itself or part of a verb construction

The accent also shows the stressed vowel quality. So you should write és with the accent when you mean is.

Here és is the 3rd person singular of ser, meaning is.

Catalan does use both ser and estar, but not in exactly the same way as Spanish or English learners might expect. In a neutral location statement like this, ser can sound perfectly natural.

• El sac de dormir és a la tenda de campanya. = The sleeping bag is in the tent.

In some contexts, speakers may also say està, especially if they want to emphasize where something is located or its current position. But the sentence you were given is fully normal.

Catalan often uses a for location where English uses in, at, or sometimes to, depending on context.

So:

• a la tenda de campanya = in the tent / at the tent

The article is still there:

• a + la = a la

There is no contraction here. But with masculine el, you do get a contraction:

• a + el = al

For example:

• al sac = to the bag / in the bag, depending on context

Yes. That would sound more explicitly like inside the tent.

Compare:

• és a la tenda de campanya = is in/at the tent
• és dins de la tenda de campanya = is inside the tent

So dins de is more specific. The original sentence is more general and very natural.

Yes, tenda de campanya is the standard full expression for camping tent or simply tent.

Literally, it is:

• tenda = tent
• de campanya = for camping / of camp

In context, people may shorten it to just tenda if it is already clear they mean a tent.

A useful note: campanya often means campaign in other contexts, but in this expression tenda de campanya, it refers to a camping tent.

The ny in Catalan is pronounced like the ny in canyon.

So campanya sounds roughly like:

• cam-PA-nya

More precisely, the last sound is a single palatal nasal sound, similar to Spanish ñ.

A rough pronunciation guide for the whole sentence is:

• el sak de dur-MIR es a la TEN-da de cam-PA-nya

That is only approximate, but it will help you get started.

Yes, very much so.

The structure is:

• El sac de dormir = subject
• és = verb
• a la tenda de campanya = location phrase

So the pattern is basically:

• The sleeping bag
  • is
    • in the tent

That makes this sentence fairly straightforward for an English speaker.

A natural plural version would be:

• Els sacs de dormir són a la tenda de campanya.

Changes:

• el → els = the
• sac → sacs = bags
• és → són = are

So:

• Els sacs de dormir són a la tenda de campanya. = The sleeping bags are in the tent.