غرفة الانتظار هادئة.

In Arabic, the present-tense verb to be is usually not stated.

So غرفة الانتظار هادئة literally looks like:

• غرفة الانتظار = the waiting room
• هادئة = quiet

But the natural meaning is The waiting room is quiet.

This kind of sentence is called a nominal sentence in Arabic. If you wanted past or future, Arabic would usually add a verb, for example:

• كانت غرفة الانتظار هادئة = The waiting room was quiet
• ستكون غرفة الانتظار هادئة = The waiting room will be quiet

Because this is an iḍāfa construction, often called a construct phrase.

Arabic often expresses X of Y without using a separate word for of. So:

• غرفة الانتظار literally means room of the waiting
• natural English: the waiting room

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun can be definite
• if the second noun is definite, the whole phrase becomes definite

So:

• غرفة الانتظار = the waiting room
• not الغرفة الانتظار

Because غرفة ends in ة, called tāʾ marbūṭa.

When you stop on the word by itself, it is usually pronounced like -a:

• غرفة = ghurfa

But when it is connected to what follows, especially in an iḍāfa, the hidden t is pronounced:

• غرفة الانتظار = ghurfat al-intiẓār or, in smooth connected speech, ghurfatu l-intiẓār

So learners often first see ة as just -a, but it can sound like -t- when the grammar requires it.

Because غرفة is a feminine noun.

In Arabic, adjectives and predicate adjectives must agree with the noun in gender and number. Since غرفة is feminine singular, هادئة is also feminine singular.

Compare:

• هادئ = masculine singular
• هادئة = feminine singular

So the sentence uses هادئة because it matches غرفة.

Because Arabic normally puts adjectives and predicate words after the noun they relate to.

Here the sentence structure is:

• غرفة الانتظار = subject
• هادئة = predicate

So the pattern is:

• subject + predicate

You can think of it as:

• The waiting room — quiet

which Arabic uses to mean The waiting room is quiet.

Because here هادئة is not part of the noun phrase the waiting room. It is the predicate of the whole sentence.

In Arabic, predicate adjectives are usually indefinite, even when the subject is definite.

So:

• غرفة الانتظار هادئة = The waiting room is quiet

But if you want the quiet waiting room, then the adjective becomes part of the noun phrase and takes الـ:

• غرفة الانتظار الهادئة = the quiet waiting room

That is an important difference:

• هادئة = predicate, quiet
• الهادئة = attributive adjective, the quiet ...

With full case endings, the sentence is:

غرفةُ الانتظارِ هادئةٌ

Here is why:

• غرفةُ is nominative, because it is the subject
• الانتظارِ is genitive, because it is the second noun in the iḍāfa
• هادئةٌ is nominative, because it is the predicate

In slower, fully inflected MSA, those endings matter. In many real-life contexts, especially when pausing, speakers often do not pronounce all of them clearly.

A rough pronunciation is hādi'a.

Helpful breakdown:

• ها = hā
• دِ = di
• ئ = a hamza, a brief glottal stop
• final ة = -a when pausing

So there is a small break in the middle:

• haa-di-a

More exactly, it is hādiʾa, with a short catch in the throat before the last a.

In fully inflected pronunciation, it can be hādiʾatun.

It is not a finite verb here. It is a verbal noun called a maṣdar.

• انتظار = waiting
• الانتظار = the waiting

So غرفة الانتظار literally means room of waiting, which Arabic uses for waiting room.

This is very common in Arabic: a noun + a verbal noun can form expressions that English might translate with another noun.

Then you need a noun phrase, not a full sentence.

A simple form is:

غرفة انتظار هادئة

In fully inflected MSA, that could be:

غرفةُ انتظارٍ هادئةٌ
or, depending on sentence role, other case endings

This means:

• غرفة انتظار = a waiting room
• هادئة = quiet, now functioning as a normal adjective

Compare the two:

• غرفة الانتظار هادئة = The waiting room is quiet
• غرفة انتظار هادئة = a quiet waiting room