Khách tham quan đang xem cuộc triển lãm.

Khách tham quan means visitor(s), sightseer(s), or sometimes tourists/visitors to a place or exhibition, depending on context.

• khách = guest, customer, visitor
• tham quan = to visit/sightsee

Together, khách tham quan is a fixed expression meaning people who are visiting a place to look around. In this sentence, it works as the subject: the people doing the action.

In this sentence, tham quan is part of the noun phrase khách tham quan.

So the sentence is not saying:

• The guests are sightseeing and looking at the exhibition

Instead, it is saying:

• The visitors are looking at the exhibition

This is a very common feature of Vietnamese: a word or phrase that is often a verb in one sentence can be part of a noun expression in another.

For example:

• tham quan bảo tàng = to visit the museum
• khách tham quan = visitors

Đang marks an action as in progress right now. It is similar to the English be + -ing form.

So:

• xem = look at / watch / view
• đang xem = is looking at / are viewing

That is why the sentence has the sense of are viewing or are looking at.

Yes, you often can.

• Khách tham quan xem cuộc triển lãm.
  = Visitors view / visitors are viewing / visitors look at the exhibition

Without đang, the sentence is more neutral. It could describe a general action, a habitual action, or a present action depending on context.

With đang, the sentence clearly emphasizes that the action is happening now.

These verbs are related, but they are not the same:

• xem = to watch, view, look at something intentionally
• nhìn = to look, to direct your eyes toward something
• thấy = to see, to perceive

In an exhibition context, xem is the natural choice because the visitors are actively viewing the exhibition.

Compare:

• nhìn bức tranh = look at the painting
• xem triển lãm = view the exhibition
• thấy bức tranh = see the painting

So xem fits best here.

Cuộc is a classifier / measure word often used with events, organized activities, or happenings.

Examples:

• cuộc họp = meeting
• cuộc thi = competition
• cuộc chiến = war
• cuộc triển lãm = exhibition

It does not usually get translated directly into English. It is just part of how Vietnamese packages certain nouns.

In many situations, Vietnamese speakers may also simply say:

• xem triển lãm

So cuộc is natural and correct, but it is not always absolutely required in everyday speech.

Vietnamese does not use articles the way English does. There is no direct equivalent that must appear in every sentence for a/an or the.

Specificity is usually understood from:

• context
• word order
• demonstratives like này = this, đó/kia = that
• other markers if needed

So cuộc triển lãm can mean:

• an exhibition
• the exhibition

The exact meaning depends on context. If you want to make it more specific, you could say:

• cuộc triển lãm này = this exhibition
• cuộc triển lãm đó = that exhibition

Vietnamese nouns usually do not need a special plural ending like English -s.

So:

• khách tham quan can mean visitor or visitors
• the number is often understood from context

If you want to make the plural explicit, you can add words like:

• các khách tham quan = the visitors / visitors
• những khách tham quan = some visitors / the visitors

But very often Vietnamese leaves this unmarked, especially when the meaning is already clear.

Yes, it could, depending on context.

Vietnamese nouns are often number-neutral unless something in the sentence makes the number clear.

So khách tham quan could mean:

• a visitor
• the visitor
• visitors
• the visitors

In real usage, context usually tells you which one is meant. In this sentence, many learners will naturally understand it as visitors because that sounds more likely in an exhibition setting, but grammatically the phrase itself does not force a plural reading.

The word order is:

Subject + aspect marker + verb + object

So here:

• Khách tham quan = subject
• đang = aspect marker
• xem = verb
• cuộc triển lãm = object

So the structure is very close to English:

• Visitors are viewing the exhibition

The main difference is that Vietnamese uses a separate word, đang, instead of changing the verb form the way English does.

Yes, a few parts may be difficult for English speakers:

• khách: the kh sound is like a breathy k sound, not exactly like English k
• đang: đ is like an English d, while plain d in Vietnamese is different
• triển lãm: both words have tones that learners often mix up
• cuộc: the ending can be clipped and short

A slow breakdown is:

• Khách
• tham quan
• đang xem
• cuộc triển lãm

It is especially important to notice that Vietnamese tones are part of the word, not optional extras. If the tones change, the word may sound wrong or become a different word.