الظلام في الغرفة.

In Modern Standard Arabic, the verb to be is usually not written in the present tense.

So الظلام في الغرفة literally looks like:

• the darkness
• in the room

But it means:

• The darkness is in the room
• or, depending on context, It is dark in the room

This is called a nominal sentence in Arabic. Arabic often expresses X is Y without a present-tense verb.

If you wanted was, then Arabic would use a verb, for example:

• كان الظلام في الغرفة = The darkness was in the room

It is a nominal sentence (جملة اسمية).

Its two main parts are:

• الظلام — the subject/topic (مبتدأ)
• في الغرفة — the predicate/comment (خبر), specifically a prepositional phrase

So the structure is:

• الظلام = the darkness
• في الغرفة = in the room

Arabic allows a prepositional phrase to serve as the predicate, so the whole sentence is perfectly normal.

The prefix الـ means the.

So:

• ظلام = darkness
• الظلام = the darkness

In this sentence, الظلام is definite. That can make the sentence sound like the darkness is in the room.

In actual usage, Arabic sometimes uses this kind of definite noun in a way that English might translate more naturally as it is dark in the room, depending on context.

في means in.

It is a very common preposition in Arabic. Here it introduces the location:

• في الغرفة = in the room

Like English prepositions, Arabic prepositions are followed by a noun. In formal grammar, the noun after a preposition is in the genitive case.

الغرفة means the room, while غرفة means a room.

So:

• في غرفة = in a room
• في الغرفة = in the room

The sentence you have uses the definite form, so it refers to a specific room.

After a preposition like في, the noun is grammatically in the genitive case.

So in full vowelled Arabic, this would be:

• الظلامُ في الغرفةِ

Notice the ending:

• الغرفةِ ends with -i because it comes after في

In normal unvowelled writing, this case ending is usually not shown, so you just see الغرفة.

It is pronounced approximately:

• aẓ-ẓalaam

This happens because ظ is a sun letter, so the ل of الـ is not pronounced separately. Instead, the following consonant is doubled.

So although it is written:

• الظلام

it is pronounced more like:

• aẓ-ẓalaam

Not al-ẓalaam.

A careful pronunciation is approximately:

• aẓ-ẓalaamu fii l-ghurfah
• or with full case endings: aẓ-ẓalaamu fii l-ghurfati

A few notes:

• الظلام → aẓ-ẓalaam
• في → fii
• الغرفة → al-ghurfah in pause, or al-ghurfati with full case ending in connected formal reading

In everyday reading, learners often say:

• aẓ-ẓalaam fii l-ghurfa

and that is usually understood fine.

Literally, it is closer to:

• The darkness is in the room

But in natural English, depending on context, it may be understood as:

• It is dark in the room

Arabic often uses nouns in ways that English may translate with an adjective or a different structure.

A more directly adjectival way to say The room is dark would be:

• الغرفة مظلمة

So the exact best translation depends on what nuance is intended.

It can. Arabic has more than one natural way to express this idea.

Your sentence uses the noun:

• الظلام = darkness

So it presents darkness as a thing/state located in the room.

Another common way is with an adjective:

• الغرفة مظلمة = The room is dark

The difference is roughly:

• الظلام في الغرفة = emphasis on darkness being present in the room
• الغرفة مظلمة = emphasis on the room being dark

Both are valid, but they are not exactly the same in style or focus.

الظلام في الغرفة is the more straightforward order for a nominal sentence:

• subject first
• predicate second

So:

• الظلام = topic/subject
• في الغرفة = what is being said about it

You may also see different word orders in Arabic for emphasis or style, but the basic learner-friendly analysis of this sentence is:

• The darkness
  • is in the room

Yes. In fully vowelled formal Arabic, the sentence would usually be:

• الظلامُ في الغرفةِ

The endings are:

• الظلامُ = -u because it is the subject of a nominal sentence
• الغرفةِ = -i because it follows the preposition في

These endings are usually omitted in normal Arabic writing, so learners often do not see them at first.

Yes, غرفة is a feminine noun.

You can often tell because it ends in ة (taa marbuuṭa).

In this particular sentence, its femininity does not change much on the surface, because it comes after a preposition:

• في الغرفة

But if you described it with an adjective, the adjective would need to match in gender:

• الغرفة مظلمة = The room is dark

Here مظلمة is feminine to agree with الغرفة.

Yes, that is possible, but it is a different structure and nuance.

• في الغرفة ظلام = There is darkness in the room
• الظلام في الغرفة = The darkness is in the room / It is dark in the room

The version starting with في الغرفة can sound more like an existential statement: there is...

So both are possible, but they are not exactly identical in emphasis.