El nostre departament prepara un informe nou per a una clienta de la ciutat.

In Catalan, possessives are very often used with a definite article:

• el meu llibre = my book
• la nostra oficina = our office
• el nostre departament = our department

This is different from English, where you normally say just our department without the.

There are some exceptions, but in ordinary statements like this one, article + possessive + noun is the normal pattern.

Because the possessive has to agree with the noun it describes.

Here the noun is departament, which is:

• masculine
• singular

So the correct form is nostre.

The basic forms are:

• nostre = masculine singular
• nostra = feminine singular
• nostres = masculine or feminine plural

Examples:

• el nostre departament
• la nostra empresa
• els nostres informes
• les nostres clientes

Prepara is the 3rd person singular present indicative form of preparar.

It matches the subject:

• El nostre departament = our department

Since department is grammatically singular, the verb is singular too:

• el departament prepara = the department prepares

Even though a department contains many people, it is treated as one unit, so Catalan uses the singular verb.

It can often mean either prepares or is preparing, depending on context.

Catalan simple present is broader than English simple present. It can express:

• a habitual action: prepares
• a current action: is preparing
• sometimes even a near future idea, depending on context

So prepara does not force just one English translation by itself.

In Catalan, adjectives often come after the noun, so:

• un informe nou = a new report

That is the most neutral, straightforward order here.

If you say un nou informe, it is also possible, but it can sound a bit different in nuance. Very often nou before the noun suggests something like:

• another new report
• a further report
• or a more stylistically marked phrasing

So:

• un informe nou = a report that is new
• un nou informe = often more like another/new additional report

The exact nuance depends on context, but this difference is very common and useful to notice.

Because informe is a masculine singular noun.

The adjective must agree with the noun:

• informe nou = masculine singular
• carta nova = feminine singular
• informes nous = masculine plural
• cartes noves = feminine plural

So nou matches informe.

Here per a marks the intended recipient or beneficiary:

• per a una clienta = for a client

In more formal or careful Catalan, per a is often used when something is meant for someone or for some purpose.

However, you should know that in everyday speech many speakers often use just per in places where formal grammar would prefer per a. So you may hear:

• per una clienta

But in standard written Catalan, per a una clienta is very natural here.

This is a classic learner question, because usage varies.

A useful basic guideline is:

• per often relates to cause, means, exchange, movement through, duration, agent
• per a often relates to destination, purpose, intended use, recipient

In this sentence, the report is being prepared for someone, so per a fits well.

That said, real-life usage is not always perfectly strict, especially in spoken Catalan. Different regions and speakers may simplify the distinction.

Yes, clienta is the normal feminine form of client.

• un client = a male client / a client
• una clienta = a female client

Catalan regularly forms many feminine nouns this way:

• amic / amiga
• alumne / alumna
• client / clienta

So una clienta is completely standard.

In the most natural reading, de la ciutat describes una clienta:

• una clienta de la ciutat = a client from the city / a city client

So the structure is:

• [El nostre departament] [prepara] [un informe nou] [per a una clienta de la ciutat].

In other words, it is the client who is connected to the city, not the report.

Because Catalan normally uses an article in this kind of phrase with a specific count noun:

• de la ciutat = of/from the city

Leaving out the article here would sound unnatural in standard Catalan.

Also notice that ciutat is feminine singular, so the article is la.

Because Catalan only contracts certain combinations, especially with el:

• de + el = del
• a + el = al

But with la, there is no contraction:

• de + la = de la
• a + la = a la

So:

• de la ciutat is correct
• not dela ciutat

Some parts could move in certain contexts, but the given order is the most neutral and natural.

Current order:

• El nostre departament
• prepara
• un informe nou
• per a una clienta de la ciutat

This follows a very common Catalan pattern:

subject + verb + object + complements

You could change the order for emphasis, but that would usually sound more marked, not more basic. For a learner, the sentence as given is an excellent model of normal word order.