Chương này dài.

• chương = chapter
• này = this
• dài = long

So chương này means this chapter, and dài describes it.

The sentence structure is:

noun phrase + adjective

So literally it is something like this chapter long, which in natural English becomes This chapter is long.

In Vietnamese, words like this and that usually come after the noun, not before it.

So:

• chương này = this chapter
• chương đó = that chapter

This is a very common pattern in Vietnamese:

• sách này = this book
• nhà này = this house

So even though English says this chapter, Vietnamese says chapter this in word order.

Vietnamese often does not use a verb like to be when an adjective is the predicate.

So:

• Chương này dài. = This chapter is long.
• Cuốn sách này hay. = This book is good/interesting.

In English, you need is. In Vietnamese, you usually do not.

That is one of the most important grammar patterns to get used to.

Normally, no. Chương này là dài is not the natural way to say it.

With adjectives like dài, Vietnamese usually just says:

• Chương này dài.

The word là is more commonly used to link two nouns or noun phrases, such as:

• Anh ấy là giáo viên. = He is a teacher.

So for This chapter is long, you usually do not use là.

It is best understood here as an adjective meaning long.

But in Vietnamese, adjectives can act directly as the main predicate of a sentence, without needing to be. That is why it may look a little verb-like to English speakers.

So in Chương này dài., dài is an adjective functioning as the main descriptive part of the sentence.

It can mean both, depending on context.

• For physical length: Cái bàn dài. = The table is long.
• For something like a chapter, speech, movie, or document: dài usually means long/lengthy

So in Chương này dài., the meaning is more like This chapter is lengthy or This chapter is long in content.

A simple learner-friendly guide:

• chương: roughly like chu-uhng, with a level tone
• này: roughly like nye, with a falling tone
• dài: roughly like yai or zai depending on accent, with a falling tone

A few helpful notes:

• In northern Vietnamese, d sounds like z
• In southern Vietnamese, d sounds more like y
• chương has the ươ vowel combination, which takes practice

The tones matter, so it is good to listen to native audio if possible.

The pattern is:

noun + demonstrative + adjective

More specifically:

• chương này = this chapter
• dài = adjective describing it

So the full pattern is:

[thing] + [this/that] + [description]

Examples:

• Nhà này lớn. = This house is big.
• Bài này khó. = This lesson is difficult.
• Phim đó hay. = That movie is good.

Yes. That is completely natural.

• Chương này dài. = This chapter is long.
• Chương này rất dài. = This chapter is very long.

The word rất means very and goes before the adjective.

You can also hear:

• Chương này dài quá. = This chapter is too long / so long
• Chương này hơi dài. = This chapter is a bit long

You usually put không before the adjective:

• Chương này không dài. = This chapter is not long.

This is the normal way to negate descriptive sentences like this.

Compare:

• Chương này dài. = This chapter is long.
• Chương này không dài. = This chapter is not long.

A very common way is to add không at the end:

• Chương này dài không? = Is this chapter long?

Another common spoken pattern is:

• Chương này có dài không? = Is this chapter long?

Both are natural. For beginners, ... dài không? is a very useful pattern to learn.

No. Chương is the actual noun meaning chapter.

Vietnamese often uses classifiers with many nouns, but not every noun in every sentence needs one. Here, chương này is just a straightforward noun phrase meaning this chapter.

So you do not need a separate classifier in this sentence.

Not exactly. It depends on context.

• chương = chapter
• bài can mean lesson, article, exercise, song, or piece, depending on context

So:

• Chương này dài. = This chapter is long.
• Bài này dài. = This lesson/article/exercise is long.

They are grammatically similar, but the noun changes the meaning.

The opposite is ngắn, meaning short.

So:

• Chương này dài. = This chapter is long.
• Chương này ngắn. = This chapter is short.

This pair is very useful:

• dài = long
• ngắn = short

Yes. It is short, simple, and natural.

Native speakers often use exactly this kind of sentence:

• Sách này hay.
• Nhà đó đẹp.
• Bài này khó.
• Chương này dài.

In conversation, they may add words for emphasis, such as quá, rất, or hơi, but the basic sentence is perfectly natural on its own.