Chất liệu của chiếc váy là vải cotton.

Chất liệu means material or what something is made of. In clothing, it usually refers to the fabric or material composition.

So chất liệu của chiếc váy means the material of the dress.

Của connects two nouns and often works like of in English.

So:

• chất liệu của chiếc váy = the material of the dress

It shows that the material belongs to, or is associated with, the dress.

Chiếc is a classifier. Vietnamese often uses classifiers before nouns, especially when talking about individual objects.

Here:

• chiếc váy = a/the dress

For clothing and other single physical items, chiếc is a common classifier. It makes the sentence sound natural and complete.

Yes, often you can.

• cái váy is more general and very common in everyday speech.
• chiếc váy can sound a bit more specific, descriptive, or slightly more polished.

In many situations, both are understood. For a learner, it is good to know that cái is a very common general classifier, while chiếc is often used for items like vehicles, bags, dresses, and other individual objects.

Là works like is in this sentence.

The structure is:

• Chất liệu của chiếc váy = the material of the dress
• là = is
• vải cotton = cotton fabric

So the full sentence is an identification/equation sentence: X is Y.

Vải means fabric/cloth. So vải cotton means cotton fabric.

You may hear people simply say cotton in casual speech, especially because this word is widely borrowed into Vietnamese. But vải cotton is clearer because it explicitly names the material as a type of fabric.

A very close word-for-word breakdown is:

• Chất liệu = material
• của = of
• chiếc váy = the dress
• là = is
• vải cotton = cotton fabric

So literally, it is:

Material of the dress is cotton fabric.

That is normal Vietnamese word order for this kind of sentence.

Sometimes yes, but it depends on what you want to say.

• Chất liệu của chiếc váy là vải cotton.
  This sounds natural when talking about a specific dress.

• Chất liệu của váy là vải cotton.
  This is less natural if you mean one specific dress. It can sound incomplete or less smooth.

If you are talking about dresses in general, you would normally change the whole sentence anyway, for example:

• Váy này làm bằng vải cotton. = This dress is made of cotton fabric.

So for a specific item, keeping chiếc is a good choice.

Yes, it is correct and natural, especially in a descriptive or slightly formal context, such as shopping, product descriptions, or discussing clothing details.

In more everyday speech, people might also say:

• Chiếc váy này làm bằng vải cotton.
• Váy này là vải cotton.
• Váy này bằng cotton.

These can sound more conversational, depending on context.

Yes. The pattern is very useful:

• Chất liệu của + noun + là + material

Examples:

• Chất liệu của chiếc áo là vải lanh.
  The shirt’s material is linen.

• Chất liệu của cái túi là da.
  The bag’s material is leather.

• Chất liệu của bộ sofa là vải nhung.
  The sofa set’s material is velvet.

So this is a good general pattern for talking about materials.

It is partly borrowed. Vải is Vietnamese, while cotton is a loanword from English that is very common in Vietnamese.

So vải cotton is a normal modern Vietnamese expression. Learners will often see this kind of mix in vocabulary for clothing, technology, food, and brand-related language.

A good takeaway is this structure:

• [noun 1] của [noun 2] là [noun 3]

In this sentence:

• noun 1 = chất liệu
• noun 2 = chiếc váy
• noun 3 = vải cotton

So the sentence means:

• The material of the dress is cotton fabric.

It is a very useful pattern for describing ownership, relationships between nouns, and basic identification.