Khuôn nứt ở trên kệ bên lò nung.

A word-by-word breakdown is:

• khuôn = mold / mould / form
• nứt = cracked / to crack
• ở = to be at / in / on; marks location
• trên = on / above
• kệ = shelf
• bên = beside / next to
• lò nung = kiln

So the sentence is built from a noun phrase plus a location phrase.

A natural way to parse it is:

• Khuôn nứt = the cracked mold
• ở trên kệ = is on the shelf
• bên lò nung = beside the kiln

So the overall structure is:

[noun + description] + [location]

Vietnamese often puts descriptive words after the noun, not before it as English does.

Because Vietnamese usually places modifiers after the noun.

So:

• khuôn nứt = cracked mold
• literally something like mold cracked

This is very normal in Vietnamese. English says the cracked mold, but Vietnamese tends to say mold cracked.

It can function as either, depending on context. That is very common in Vietnamese.

Here, the most likely reading is that nứt is describing the state of khuôn, so:

• khuôn nứt = the cracked mold

In other contexts, nứt can also act more like a verb:

• Cái ly nứt rồi = The cup has cracked / is cracked now

So for learners, it is often best to think of words like nứt as flexible state words that can behave like adjectives or verbs.

Vietnamese does not use is the same way English does.

For location, Vietnamese commonly uses ở:

• ở trên kệ = is on the shelf

So ở is doing the job of expressing location. You do not use là here.

Compare:

• Nó là bác sĩ = He/She is a doctor
• Nó ở trên kệ = It is on the shelf

In your sentence, ở is the important word for the location.

Trên means on / above, while ở marks that something is located somewhere.

So:

• trên kệ = on the shelf
• ở trên kệ = is on the shelf

In many cases, both are possible, but ở trên makes the locational meaning more explicit. It helps show that the sentence is telling you where something is.

Most naturally, it describes kệ:

• trên kệ bên lò nung = on the shelf beside the kiln

So the shelf is beside the kiln.

That is the most likely reading, rather than saying the mold itself is somehow beside the kiln separately.

If someone wanted to make that relationship extra clear, they might say something like:

• ở trên cái kệ bên lò nung

But your original sentence is already understandable.

Lò nung is a compound noun:

• lò = furnace / oven / kiln
• nung = to heat intensely / to fire

Together, lò nung usually means kiln, especially in a ceramics or industrial context.

So in this sentence, it suggests a place where something is fired or heated at high temperature.

Vietnamese does not have articles that work like English a and the.

So khuôn can mean:

• a mold
• the mold

Context tells you which one is meant.

The same is true for kệ and lò nung. English translations have to choose a or the, but Vietnamese often leaves that unstated.

Vietnamese classifiers are common, but they are not always required.

You could say:

• cái khuôn nứt

But in short written descriptions, labels, notes, or when the noun is already clear from context, the classifier is often omitted.

So both of these can work, depending on style and context:

• Khuôn nứt ở trên kệ bên lò nung.
• Cái khuôn nứt ở trên kệ bên lò nung.

The second can sound a little more conversational or concrete.

It could be interpreted that way in some contexts, because Vietnamese words like nứt are flexible and Vietnamese often allows compact phrasing.

However, many learners will most naturally read khuôn nứt here as the cracked mold, especially because the sentence continues with a location phrase.

So the default reading is usually:

• The cracked mold is on the shelf beside the kiln.

If someone wanted to make the event meaning clearer, they might use a different wording, depending on context.