Mặc dù bị móp nhưng va li nguyên vẹn.

It sets up a contrast, like although/even though ... but ....

In this sentence:

• Mặc dù bị móp = although it was dented
• nhưng va li nguyên vẹn = but the suitcase was intact

This is a very common Vietnamese structure. In English, although ... but ... is usually avoided, but in Vietnamese using both parts is normal.

Bị often marks that something happened to the subject in an unwanted or negative way.

So:

• móp = dented, caved in
• bị móp = got dented / was dented

It is similar to a passive idea, but with an extra sense that the result is unfavorable. That is why bị fits well here.

Vietnamese often leaves out a subject when it is obvious from context.

Here, the omitted subject is the suitcase. So the full idea is basically:

• Mặc dù va li bị móp, nhưng va li nguyên vẹn.

Repeating va li twice would sound a bit heavy, so Vietnamese often omits it in the first clause.

Vietnamese often does not use a copula like is/are/was/were before adjectives or stative descriptions.

So:

• va li nguyên vẹn literally looks like suitcase intact
• but it means the suitcase is/was intact

This is very normal Vietnamese grammar.

Móp means dented, caved in, or pressed inward, usually on something with a firm surface.

For example, a suitcase, car door, or metal container can be móp.

It is more specific than a general word like damaged. It suggests a physical dent rather than total breakage.

Because nguyên vẹn does not necessarily mean perfectly without any mark. It means still intact, still whole, not broken apart, or not seriously damaged overall.

So the sentence means something like:

• it had a dent
• but it was still basically intact

That is not contradictory. A suitcase can have a dent and still remain structurally fine.

Nguyên vẹn means intact, whole, undamaged overall, or complete.

It is often used for things that remain in one piece or unharmed:

• đồ đạc còn nguyên vẹn = the belongings are still intact
• ngôi nhà còn nguyên vẹn = the house is still intact

In this sentence, it emphasizes that the suitcase was not ruined despite the dent.

Yes. In fact, many learners will also see:

• Mặc dù bị móp nhưng va li vẫn nguyên vẹn.

Here vẫn means still. It makes the contrast even clearer:

• dented, but still intact

The original sentence without vẫn is still grammatical and understandable. Adding vẫn just makes the concessive meaning more explicit.

Yes.

You can say:

• Dù bị móp nhưng va li nguyên vẹn.

Dù is shorter and often a bit less formal.
Mặc dù sounds slightly fuller or more formal, but both are common and natural.

Not always.

You can say:

• Mặc dù bị móp nhưng va li nguyên vẹn.
• Mặc dù bị móp, va li vẫn nguyên vẹn.

Both are possible.

Using nhưng makes the contrast very explicit. Leaving it out can sound a little more streamlined, especially if vẫn is present in the main clause.

Both spellings are used.

• va li is the syllable-separated spelling
• vali is also very common in modern writing

Vietnamese traditionally writes many multisyllabic loanwords with a space between syllables, so va li is completely normal.

Because classifiers are not always required.

You could say:

• nhưng va li nguyên vẹn
• nhưng chiếc va li nguyên vẹn

Both are natural. Adding chiếc makes the noun phrase feel a bit more specific or concrete, but leaving it out is also normal, especially in short descriptive sentences like this one.