Chi nhánh này đông lắm.

In Vietnamese, demonstratives like này (this) usually come after the noun.

So:

• chi nhánh này = this branch
• literally: branch this

This is a very common Vietnamese word order:

• nhà này = this house
• người này = this person
• công ty này = this company

So chi nhánh này is the normal way to say this branch.

Chi nhánh means branch, especially a branch of a company, bank, chain store, organization, etc.

It is a fixed noun phrase:

• chi = branch/subdivision
• nhánh = branch/offshoot

Together, chi nhánh is the standard word for a business or organizational branch location.

For example:

• chi nhánh ngân hàng = bank branch
• chi nhánh công ty = company branch

So in this sentence, chi nhánh này means this branch.

Vietnamese often does not use a word equivalent to English is/are before adjectives or descriptive states.

In English, you say:

• This branch is crowded.

In Vietnamese, you can simply say:

• Chi nhánh này đông.

Here, đông works like a descriptive word meaning crowded / having many people. Vietnamese does not need a separate is in this kind of sentence.

This is very common:

• Cô ấy đẹp. = She is beautiful.
• Trời nóng. = The weather is hot.
• Nơi này đông. = This place is crowded.

Here, đông means crowded, busy, or having a lot of people.

So Chi nhánh này đông means that this branch has many people there.

Depending on context, it could suggest:

• lots of customers
• lots of visitors
• a busy branch
• a crowded location

It does not mean there are many branches. It means this particular branch has a lot of people in it.

Lắm adds emphasis. In this sentence, it means something like:

• very
• a lot
• really

So:

• Chi nhánh này đông. = This branch is crowded.
• Chi nhánh này đông lắm. = This branch is very crowded / really busy.

Sentence-final lắm is very common in spoken Vietnamese and sounds natural and expressive.

Examples:

• Đẹp lắm. = Very beautiful.
• Mệt lắm. = Very tired.
• Vui lắm. = Very fun / very happy.

Both can mean very crowded, but the feeling is a little different.

• rất đông = more neutral, straightforward, a bit more formal
• đông lắm = more natural in conversation, often more expressive or emphatic

So these are both possible:

• Chi nhánh này rất đông.
• Chi nhánh này đông lắm.

In everyday speech, đông lắm often sounds more lively and conversational.

Đông can have other meanings in Vietnamese depending on context, so learners sometimes get confused.

Common meanings include:

• đông = crowded / numerous
• Đông = East
• mùa đông = winter

In Chi nhánh này đông lắm, the context clearly shows that đông means crowded / busy with many people.

This is normal in Vietnamese: the same written form can have different meanings, and context tells you which one is intended.

It is talking about the branch as a place, but really describing the number of people there.

So when someone says:

• Chi nhánh này đông lắm.

they mean:

• This branch has a lot of people.
• This branch is very crowded.
• This branch is really busy.

Vietnamese often describes places this way. The place is the grammatical subject, but the idea is really about the people present there.

Yes. This sentence pattern is very useful:

• [place] + này + đông lắm

It means This [place] is very crowded.

For example:

• Quán này đông lắm. = This café/restaurant is very crowded.
• Siêu thị này đông lắm. = This supermarket is very crowded.
• Chỗ này đông lắm. = This place is very crowded.
• Ngân hàng này đông lắm. = This bank is very crowded.

So the structure is easy to reuse.

A natural English translation could be:

• This branch is very crowded.
• This branch is really busy.
• This branch has a lot of people.

The best choice depends on context:

• crowded focuses on many people being there
• busy often sounds more natural for a bank branch, office, or store

So if this is, for example, a bank or service location, This branch is really busy may sound especially natural.