Máy điều hòa rất mới.

In Vietnamese, you usually do not use a copula like is/are before adjectives.

So:

• Máy điều hòa rất mới = The air conditioner is very new

Structure:

• Máy điều hòa = air conditioner
• rất mới = very new

This is completely normal Vietnamese sentence structure.

If you add là here, it would sound unnatural in standard Vietnamese:

• natural: Máy điều hòa rất mới
• unnatural for this meaning: Máy điều hòa là rất mới

Là is mainly used when linking one noun to another, not usually before an adjective.

Vietnamese adjectives typically come after the noun they describe.

So:

• máy điều hòa mới = new air conditioner
• literally: air conditioner new

This is one of the biggest word-order differences from English.

Compare:

• English: new air conditioner
• Vietnamese: máy điều hòa mới

In the full sentence:

• Máy điều hòa rất mới
  the adjective phrase rất mới comes after the noun phrase máy điều hòa.

Rất means very.

In Vietnamese, degree words like rất usually come before the adjective.

So:

• mới = new
• rất mới = very new

More examples:

• rất tốt = very good
• rất đẹp = very beautiful
• rất lạnh = very cold

So the pattern is:

• noun + rất
  • adjective

Example:

• Cái bàn rất đẹp = The table is very beautiful

Here, máy is not a classifier. It is a normal noun meaning machine/device.

Máy điều hòa is a compound noun meaning air conditioner.

Breakdown:

• máy = machine, device
• điều hòa = regulate, balance, air-condition

Together:

• máy điều hòa = air conditioner

So in this sentence, máy điều hòa functions as one noun phrase.

It is similar to how English combines words into one object name, even if the parts are still understandable.

Yes, very often in everyday speech, people simply say điều hòa to mean air conditioner.

So both of these are common:

• Máy điều hòa rất mới
• Điều hòa rất mới

The longer form máy điều hòa is a bit more explicit.
The shorter form điều hòa is very common in conversation.

A learner should recognize both.

Mới most commonly means new, but it can also have other meanings in different contexts.

In this sentence:

• mới = new

But elsewhere, mới can be part of expressions meaning things like:

• just
• recently
• only then

For example:

• Tôi mới ăn xong = I just finished eating

So context matters.

In Máy điều hòa rất mới, there is no ambiguity: mới clearly means new.

Vietnamese does not use articles the same way English does.

So:

• máy điều hòa can mean the air conditioner, an air conditioner, or simply air conditioners depending on context

In this sentence, the exact English article must be decided from the situation.

If you want to be more specific, Vietnamese often uses words like:

• này = this
• kia = that
• một = one / a

Examples:

• Máy điều hòa này rất mới = This air conditioner is very new
• Một máy điều hòa rất mới = A very new air conditioner

So the basic sentence leaves definiteness unstated.

It is a complete sentence.

Vietnamese can make a full sentence with:

• noun phrase + adjective phrase

So:

• Máy điều hòa = subject
• rất mới = predicate

This is enough to express The air conditioner is very new.

It is not just a noun phrase like very new air conditioner.
If it were only a noun phrase, it would more naturally be:

• máy điều hòa rất mới in the right context could still be read as a noun phrase, but as a standalone statement, it is naturally understood as a full sentence.

Vietnamese often allows this kind of adjective predicate without any extra verb.

A rough English-friendly guide is:

• Máy ≈ like my with a rising tone
• điều ≈ roughly zee-oo or yew with Vietnamese vowel quality and a falling-glottal tone
• hòa ≈ roughly hwa with a low falling tone
• rất ≈ roughly zut or ruht with a cut-off tone
• mới ≈ roughly muh-ee or moy with a rising-glottal tone

A few important notes:

• Vietnamese pronunciation does not match English exactly
• tones are essential
• đ is not the same as English d; it is closer to an unaspirated d
• southern and northern accents will sound different

If you are learning pronunciation, it is best to hear this from native audio rather than rely only on English approximations.

Yes, it is natural and standard.

A native speaker would easily understand it as:

• The air conditioner is very new

It sounds especially natural when talking about the condition of something in a room, house, hotel, office, or apartment.

For example:

• Máy điều hòa rất mới, nên chạy tốt lắm.
  The air conditioner is very new, so it works very well.

If you want to sound a bit more contextual in conversation, you might often hear:

• Máy điều hòa này rất mới = This air conditioner is very new

But the original sentence is perfectly fine on its own.

Not for this meaning.

You would not normally say:

• mới máy điều hòa

That word order is wrong for a simple adjective meaning new.

In Vietnamese, the normal pattern is:

• noun + adjective

So:

• correct: máy điều hòa mới
• wrong: mới máy điều hòa

If you see mới before something, it is usually because it has a different function, such as just/recently, not because it is directly describing a noun.

You can add demonstratives or other details.

Common options:

• Máy điều hòa này rất mới = This air conditioner is very new
• Máy điều hòa kia rất mới = That air conditioner is very new
• Cái máy điều hòa này rất mới = This air conditioner is very new

About cái:

• cái is a common classifier for many objects
• in casual speech, speakers may include it or leave it out depending on style and emphasis

So all of these may be heard:

• Máy điều hòa rất mới
• Máy điều hòa này rất mới
• Cái máy điều hòa này rất mới

They differ more in specificity and style than in core meaning.