Áo sơ mi này làm bằng vải cotton.

Áo sơ mi means shirt, especially a button-up shirt / dress shirt / collared shirt.

• áo = shirt, top, garment
• sơ mi = specifically the shirt type

In modern Vietnamese, áo sơ mi is treated as a fixed phrase, so learners usually memorize it as one unit.

In Vietnamese, demonstratives like this and that usually come after the noun.

So:

• áo sơ mi này = this shirt
• literally: shirt this

This is normal Vietnamese word order. English says this shirt, but Vietnamese says shirt this.

Yes. Cái áo sơ mi này is also correct.

• cái is a common classifier for objects.
• áo sơ mi này = perfectly fine
• cái áo sơ mi này = also fine, often a bit more explicit or conversational

In many everyday sentences, the classifier is optional when the meaning is already clear.

Làm bằng means made of / made from / made with, depending on context.

Here it tells you the material of the shirt.

• làm = make
• bằng = with, by, of

So làm bằng vải cotton means made of cotton fabric.

In natural English, you would usually translate the whole sentence as This shirt is made of cotton.

Vietnamese often does not need a word equivalent to English is in sentences like this.

English:

• This shirt is made of cotton.

Vietnamese:

• Áo sơ mi này làm bằng vải cotton.

Vietnamese does not need a separate is before làm bằng here. The predicate works without it.

Also, you would not normally use là here:

• Áo sơ mi này là làm bằng... = unnatural / incorrect

If you want a more explicit passive-style sentence, Vietnamese often says:

• Áo sơ mi này được làm bằng vải cotton.

Vải means fabric / cloth.

So:

• vải cotton = cotton fabric

The sentence is emphasizing the material more specifically. It is a bit like saying:

• made of cotton fabric

In everyday speech, people may sometimes shorten it depending on context, but vải cotton is very common in clothing descriptions, labels, and product information.

In Vietnamese, the main noun often comes first, and the material/type word follows it.

So:

• vải cotton = cotton fabric
• literally: fabric cotton

This is a very common Vietnamese pattern:

• áo trắng = white shirt
• bàn gỗ = wooden table
• vải cotton = cotton fabric

English usually puts the describing word before the noun, but Vietnamese often puts it after.

Both can often be translated as made of / made from, but there is a small difference in feeling.

• làm bằng often emphasizes the material used
• làm từ can sound a little broader, like something is created from a source material

For clothing and materials, both may appear, but làm bằng vải cotton sounds very natural when talking about what material something is made of.

Examples:

• Bàn làm bằng gỗ. = The table is made of wood.
• Rượu làm từ gạo. = Alcohol is made from rice.

In real usage, the distinction is not always strict, but this is a useful guideline.

Cotton is a borrowed word that is very commonly used in Vietnamese, especially in fashion, shopping, and product descriptions.

So vải cotton is completely normal Vietnamese.

You may also learn other related words, but in modern everyday usage, especially for clothes, cotton is extremely common.

Yes, it is natural, especially in contexts like:

• clothing descriptions
• shopping
• product labels
• sales talk

A slightly fuller version is also common:

• Áo sơ mi này được làm bằng vải cotton.

That version sounds a bit more explicit and formal because được helps create a passive-like meaning, similar to is made of in English.

So both are useful:

• Áo sơ mi này làm bằng vải cotton.
• Áo sơ mi này được làm bằng vải cotton.

The structure is:

• Áo sơ mi này = subject noun phrase = this shirt
• làm bằng vải cotton = predicate = made of cotton fabric

Word-for-word, it is roughly:

• Áo sơ mi này = shirt this
• làm bằng = made of / made with
• vải cotton = cotton fabric

So the sentence is built very straightforwardly: [thing] + [material information]

A rough pronunciation guide is:

• Áo ≈ ow with a rising tone
• sơ ≈ suh / sur (without a strong English r)
• mi ≈ mee
• này ≈ nye with a falling tone
• làm ≈ lahm with a falling tone
• bằng ≈ bung / bahng with a falling tone
• vải ≈ vai with a dipping/asking tone
• cotton is pronounced similarly to the borrowed form used in Vietnamese speech

A very rough full approximation is: ow suh mee nye lahm bung vai cotton

But it is important to learn the tones from audio, because tones matter a lot in Vietnamese.

Not usually by itself in this kind of sentence. Này normally follows a noun:

• áo này = this shirt
• áo sơ mi này = this shirt

If you want to say this one, Vietnamese more often uses something like:

• cái này = this one

So in your sentence, này works because it is attached to the noun phrase áo sơ mi.