للأسف، خدمة الغرف غير متاحة.

Yes. للأسف is a very common fixed expression meaning unfortunately. It is used to introduce bad news, disappointment, or something regrettable.

You can think of it as a set phrase rather than translating each part every time.

Because it comes from:

• لِـ = a preposition meaning for / to
• الأسف = regret / sorrow

When لِـ joins a word beginning with الـ, Arabic writes both ل letters together:

• لِ + الأسف → للأسف

It is commonly pronounced roughly lil-ʾasaf.

It is an iḍāfa construction, often called a genitive construction or noun-noun phrase.

Literally, it means:

• خدمة = service
• الغرف = the rooms

So word-for-word it is service of the rooms, which is how Arabic expresses room service.

Because in an iḍāfa construction, the first noun usually does not take الـ. The definiteness comes from the second noun.

So:

• خدمة الغرف = the room service

Even though خدمة has no الـ, the whole phrase is definite because الغرف is definite.

This is just the normal Arabic expression for room service: خدمة الغرف.

Literally it means service of the rooms, referring to hotel rooms in general. Arabic often uses the plural in this kind of set phrase. So even though English says room service with singular room, Arabic uses rooms.

It is not stated explicitly. In the present tense, Arabic often uses a nominal sentence with no written word for is / are.

So:

• خدمة الغرف غير متاحة
• literally: room service not available
• natural English: Room service is unavailable

This is completely normal in Arabic.

Because غير + adjective is a very common way in Arabic to say not / non- / un-.

Here:

• متاحة = available
• غير متاحة = not available / unavailable

This structure is especially common in formal Arabic, notices, signs, and customer-service language.

A different but also correct way would be:

• خدمة الغرف ليست متاحة

That also means Room service is not available.
But غير متاحة sounds concise and very natural here.

Because it agrees with خدمة, which is a feminine singular noun.

So the adjective must also be feminine singular:

• خدمة → feminine
• متاحة → feminine form of available

Even though الغرف is plural, the main noun of the phrase is خدمة, so that is the word the adjective agrees with.

The basic masculine form is متاح.

So:

• متاح = available, allowed, accessible
• متاحة = feminine singular form

In this sentence, Arabic uses the feminine form because of خدمة.

A practical pronunciation is:

lil-ʾasaf, khidmat al-ghuraf ghayr mutāḥa

A few sound notes:

• خ in خدمة is a throaty sound, like the ch in German Bach
• غ in الغرف and غير is a voiced back-of-the-throat sound, somewhat like a French r
• ح in متاحة is a strong breathy h from deeper in the throat

If you are not using full case endings, the pronunciation above is the normal learner-friendly version.

Yes, literally that is close. But in natural English, room service is unavailable is much better.

That is a good example of how Arabic and English package the same idea differently:

• Arabic: service of the rooms
• English: room service

So it is best to understand خدمة الغرف as one unit.