Họ ở đây.

Họ means they.

A few useful notes:

• It is a third-person plural pronoun.
• It often sounds a bit neutral or written compared with how people speak casually.
• In everyday speech, Vietnamese may also use more specific words depending on who they are.

In Họ ở đây, họ is simply the subject: they.

Vietnamese does not always use a direct equivalent of the English verb to be in the same way English does.

In this sentence, ở does the job of expressing being at a place / staying in a place / located in a place.

So:

• Họ = they
• ở = are at / stay at / located at
• đây = here

That is why Họ ở đây naturally means They are here.

Here, ở means something like:

• to be at
• to stay at
• to be located at

It is very common when talking about location.

Examples:

• Tôi ở nhà. = I am at home.
• Cô ấy ở trường. = She is at school.
• Họ ở đây. = They are here.

Depending on context, ở can sometimes also suggest live or stay, but in this sentence the most natural meaning is simply are here.

Đây means here.

It refers to a place near the speaker.

So:

• đây = here
• đó / đấy = there
• kia = over there / yonder

In Họ ở đây, đây tells you where they are: here.

It is fairly similar.

The structure is:

Subject + ở + place

So:

• Họ = subject
• ở = be at / stay at
• đây = place

This gives: Họ ở đây = They are here

So yes, the sentence order is quite straightforward for an English speaker.

Yes, it can, depending on context.

Because ở can mean:

• to be at
• to stay
• to live

So Họ ở đây could mean:

• They are here if you are talking about current presence
• They live here if you are talking about residence

Context usually makes the meaning clear.

If you want to make live more explicit, Vietnamese often uses:

• Họ sống ở đây. = They live here.

A simple learner-friendly guide:

• họ: sounds roughly like haw with a heavy falling tone
• ở: a short vowel something like uh/er, also with a rising broken tone
• đây: roughly like day with a level-ish or slightly rising sound depending on dialect

Important details:

• họ has a dot-below tone (nặng), so it is short and heavy.
• ở has the hỏi tone.
• đ in đây is pronounced like English d, not like plain Vietnamese d.

A rough approximation: haw uh day

But it is best to learn the tones from native audio, because tones matter a lot.

Not always.

Họ is correct, but in natural conversation Vietnamese often prefers:

• a more specific noun, like mấy người đó = those people
• a kinship term, depending on who the people are
• or a fuller pronoun phrase such as bọn họ

For example:

• Bọn họ ở đây. = They are here.

Still, Họ ở đây is perfectly correct and very common in writing and clear speech.

Usually no, not for a normal full sentence meaning They are here.

You normally need ở to express location:

• Họ ở đây. = They are here.

If you say Họ đây, it sounds incomplete or unusual in most contexts.

In very special situations, short fragments can happen in speech, but as a learner, you should use: Họ ở đây.

Add không before ở:

Họ không ở đây. = They are not here.

Pattern: Subject + không + ở + place

Examples:

• Tôi không ở nhà. = I am not at home.
• Anh ấy không ở đây. = He is not here.

A very common way is:

Họ có ở đây không? = Are they here?

Pattern: Subject + có + verb + không?

You may also hear:

• Họ ở đây à? = They’re here? / Are they here?
• Họ ở đây không? = Are they here?

For learners, Họ có ở đây không? is a very clear and useful pattern.

In a simple sentence like this, yes, the location word normally comes after ở:

• Họ ở đây. = They are here.
• Tôi ở đó. = I am there.

So the usual pattern is: Subject + ở + location

That is the natural word order to learn first.