Phòng ngủ ở trong căn hộ.

• phòng ngủ = bedroom
  • phòng = room
  • ngủ = sleep
• ở = to be located / to stay / at
• trong = inside / in
• căn hộ = apartment / flat

So the whole sentence means The bedroom is in the apartment or A bedroom is in the apartment, depending on context.

Vietnamese often does not need a separate word like English is in location sentences.

In Phòng ngủ ở trong căn hộ:

• phòng ngủ is the thing being talked about
• ở trong căn hộ tells its location

Here, ở already helps express location, so you do not need a separate verb like English is.

ở trong means in / inside.

• ở marks location: being at/in some place
• trong adds the idea of inside

So:

• ở trong căn hộ = in the apartment / inside the apartment

Using both together is very common and natural. It emphasizes physical location inside something.

Yes, often you can.

• Phòng ngủ trong căn hộ can be understood as The bedroom in the apartment
• Phòng ngủ ở trong căn hộ is clearer as a full location statement: The bedroom is in the apartment

So:

• ở trong sounds more explicitly like a complete sentence about location
• trong alone can sometimes feel a little more like a descriptive phrase, depending on context

If you are a learner, ở trong is a safe and natural choice.

Usually, Phòng ngủ ở căn hộ sounds less natural if you specifically mean inside the apartment.

• ở by itself can mean at
• ở trong more clearly means inside

Because a bedroom is physically inside an apartment, ở trong căn hộ is better.

Actually, the word order is fairly similar to English here:

• Phòng ngủ = the bedroom
• ở trong căn hộ = in the apartment

So the structure is basically:

subject + location

That is very close to English: The bedroom + is in the apartment

The main difference is that Vietnamese does not need an exact equivalent of English the or is here.

It can mean either one, depending on context.

Vietnamese usually does not mark the and a/an as directly as English does. So phòng ngủ could mean:

• the bedroom
• a bedroom
• bedroom(s) in some contexts

If the meaning has already been shown to you as The bedroom is in the apartment, that is a perfectly good translation. But Vietnamese itself is often more flexible.

căn hộ means apartment, and sometimes also flat in British English.

• căn is a word often used with units like houses, apartments, rooms, etc.
• hộ is part of the compound word

Together, căn hộ is the normal word for an apartment unit in a building.

Yes.

• phòng = room
• ngủ = sleep

So phòng ngủ literally means sleeping room, but the natural English translation is bedroom.

This is very common in Vietnamese: two words combine to make one noun.

Yes, it is natural and correct.

It clearly expresses location:

• Phòng ngủ = bedroom
• ở trong căn hộ = is in the apartment

A native speaker might also say similar versions depending on context, but this sentence is normal and understandable.

A rough guide is:

Phòng ngủ ở trong căn hộ
≈ fawng ngoo uh chong gun hoh

A few notes:

• ph sounds like f
• ng in ngủ is like the ng sound in sing, but it can appear at the start of a word in Vietnamese
• tr in southern and many central accents may sound somewhat like ch
• tones matter a lot in Vietnamese, so the rough English spelling only helps a little

If you want, I can also break it down syllable by syllable with tone notes.

Yes, it could be either.

Without extra words, Vietnamese often leaves specificity to context.

If you want to make it more specific, Vietnamese can add words such as:

• một phòng ngủ = a bedroom
• phòng ngủ đó = that bedroom
• phòng ngủ này = this bedroom

But by itself, phòng ngủ can be interpreted from the situation.

Yes, but it changes the nuance slightly.

• trong = in / inside
• bên trong = inside, more explicitly emphasizing the interior

So:

• Phòng ngủ ở trong căn hộ = The bedroom is in the apartment
• Phòng ngủ ở bên trong căn hộ = The bedroom is inside the apartment

The version with bên trong can sound a bit more emphatic or descriptive.