A la terrassa del restaurant hi ha sis cadires.

A very literal breakdown is:

• A = at / on / in
• la terrassa = the terrace
• del restaurant = of the restaurant
• hi ha = there is / there are
• sis cadires = six chairs

So the whole sentence is literally something like:

On the restaurant’s terrace, there are six chairs.

Natural English would usually be:

There are six chairs on the restaurant terrace.

A la terrassa gives the location first: on the terrace.

Catalan often puts the place at the beginning of the sentence, especially when setting the scene. So:

• A la terrassa del restaurant hi ha sis cadires.
  = On the restaurant terrace, there are six chairs.

This is perfectly natural. You could also say:

• Hi ha sis cadires a la terrassa del restaurant.

Both are correct; the difference is mainly one of emphasis and information order.

Because de + el contracts to del in Catalan.

So:

• de + el = del

That is why:

• la terrassa del restaurant = the terrace of the restaurant / the restaurant’s terrace

This is very common in Catalan, just like:

• al = a + el
• del = de + el

Hi ha is the standard way to say there is or there are in Catalan.

It comes from the verb haver-hi, which is used for existence:

• Hi ha una taula. = There is a table.
• Hi ha dues finestres. = There are two windows.

In this sentence:

• hi ha sis cadires = there are six chairs

A useful point: hi is part of this expression and often does not need to be translated separately in natural English.

Because in standard Catalan, the existential expression haver-hi normally stays in the same form regardless of whether what follows is singular or plural.

So you say:

• Hi ha una cadira. = There is one chair.
• Hi ha sis cadires. = There are six chairs.

Even though English changes from is to are, Catalan usually keeps ha in this structure.

Because hi ha expresses existence: it tells you that something is present somewhere.

• Hi ha sis cadires = There are six chairs

Using són would be a different kind of sentence, based on to be, not there is/there are.

Compare:

• Hi ha sis cadires a la terrassa.
  = There are six chairs on the terrace.

• Aquestes són sis cadires.
  = These are six chairs.

So in your sentence, hi ha is the correct choice because the idea is existence/location.

That is the normal pattern with existential haver-hi:

• hi ha + noun

Examples:

• Hi ha un gat.
• Hi ha tres persones.
• Hi ha sis cadires.

The thing that exists usually comes after hi ha.
So hi ha sis cadires is the expected word order.

Because after numbers, Catalan usually does not use the article unless there is a special reason.

So:

• sis cadires = six chairs
• not les sis cadires unless you specifically mean the six chairs

Compare:

• Hi ha sis cadires. = There are six chairs.
• Hi ha les sis cadires. = The six chairs are there / All six specific chairs are there.

In your sentence, the meaning is simply a quantity, so sis cadires is correct.

Because sis means six, so the noun must be plural:

• una cadira = one chair
• sis cadires = six chairs

This is very straightforward in Catalan: if the number is more than one, the noun is normally plural.

Yes, absolutely.

Both are natural:

• A la terrassa del restaurant hi ha sis cadires.
• Hi ha sis cadires a la terrassa del restaurant.

The first version emphasizes the location first.
The second version starts with the existence statement there are.

So the difference is mostly about focus, not basic meaning.

In standard Central Catalan, hi ha is usually pronounced approximately like:

• ee AH

A few useful notes:

• hi is pronounced like a short ee
• ha has a silent h
• the stress is on ha

So:

• hi ha ≈ ee AH

Pronunciation can vary somewhat by dialect, but the h is not pronounced.

Terrassa usually refers to an outdoor seating area, terrace, or patio-like space, depending on context.

In a sentence like this:

• A la terrassa del restaurant...

it usually means the restaurant’s outdoor seating area, so in English that could be:

• on the terrace
• on the patio
• in the outdoor seating area

The exact translation depends on the setting, but terrace is the most direct match.