Sự cố ở trong căn hộ.

Sự cố is a noun. It usually means an incident, a problem, a malfunction, or trouble, depending on context.

A few common uses:

• sự cố kỹ thuật = technical problem / malfunction
• sự cố giao thông = traffic incident
• sự cố điện = power problem

So it is broader than just one English word. You choose the best English translation from the situation.

Vietnamese often does not use a separate word equivalent to English is in location sentences.

Here, ở does the job of marking location, so:

Sự cố ở trong căn hộ
literally feels like
incident located inside apartment

So even without an explicit is, the sentence is complete in Vietnamese.

trong means in / inside.
ở is often used to mark location, roughly at / in / located at.

Together, ở trong means in / inside, with a slightly clearer sense of physical location.

So:

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

In many cases, both are possible. Ở trong can sound a bit more explicit.

Not very different here.

The structure is:

Sự cố + ở trong căn hộ
incident/problem + in the apartment

So the basic order is:

• thing being talked about
• location

That is quite straightforward for an English speaker.

Yes. Căn hộ means apartment, flat, or apartment unit.

It usually refers to a unit in a larger building, not a whole house.

The word căn is a classifier-like element often used with rooms or housing units, but in căn hộ, it is best learned as part of the whole noun căn hộ.

Vietnamese does not have articles like the and an.

That means:

• sự cố could mean the incident or an incident
• căn hộ could mean the apartment or an apartment

Context tells you which meaning is intended.

It is understandable, but by itself it can sound a little short or abrupt.

If you want to say There is an incident in the apartment, Vietnamese speakers often say:

Có sự cố trong căn hộ.

If you want to say An incident happened in the apartment, a more explicit version is:

Sự cố xảy ra trong căn hộ.

So Sự cố ở trong căn hộ is possible, but it may sound more like a brief statement about location than the most natural everyday phrasing.

Yes, often you can.

• Sự cố ở trong căn hộ = the incident is inside the apartment
• Sự cố trong căn hộ = can work, but may also sound like a noun phrase such as the incident in the apartment

So ở trong makes the sentence feel more clearly like a complete location statement.

trong căn hộ means inside the apartment.

ở căn hộ is less specific. It can feel more like at the apartment rather than clearly inside it.

So if you want the meaning inside the apartment, trong căn hộ or ở trong căn hộ is better.

Syllable by syllable, it is:

sự / cố / ở / trong / căn / hộ

The tones are:

• sự = heavy, low tone
• cố = rising tone
• ở = dipping-rising tone
• trong = level tone
• căn = level tone
• hộ = heavy, low tone

A rough guide for an English speaker is:

suh + coh + uh + chong/trong + cun + hoh

That is only approximate, though. The tones matter a lot more than English-style stress.