Họ không những tuyển dụng mà còn thương lượng.

It means not only ... but also ....

So in this sentence:

• Họ không những tuyển dụng mà còn thương lượng.
• They not only recruit/hire, but also negotiate.

This is a very common Vietnamese pattern for adding emphasis. The second part gives extra information that strengthens or expands the first part.

Structure:

• không những + A + mà còn + B

Here:

• A = tuyển dụng
• B = thương lượng

Because không những is a fixed expression. In this pattern, không is not functioning as a normal negative by itself.

So you should understand không những ... mà còn ... as one whole structure meaning not only ... but also ..., not as:

• not recruit
• or some kind of simple negation

Compare:

• Họ không tuyển dụng. = They do not recruit.
• Họ không những tuyển dụng mà còn thương lượng. = They not only recruit but also negotiate.

Those are different uses of không.

Because mà còn is the normal pairing with không những in this structure.

Vietnamese often uses linked pairs like this:

• không những ... mà còn ...
• không chỉ ... mà còn ...

Here, mà works as a connector between the two parts, and còn adds the sense of also / in addition.

Using và còn here would usually sound less natural. For this specific pattern, learners should memorize it as a set phrase:

• không những ... mà còn ...

Yes, they are very close in meaning. Both can mean not only.

So these are both natural:

• Họ không những tuyển dụng mà còn thương lượng.
• Họ không chỉ tuyển dụng mà còn thương lượng.

In many contexts, they are interchangeable.

A learner-friendly rule:

• không những = not only
• không chỉ = not only

You will hear both in spoken and written Vietnamese.

Tuyển dụng means to recruit / to hire staff or employees.

It is commonly used in work, business, and HR contexts.

Examples:

• công ty đang tuyển dụng nhân viên = the company is hiring employees
• bộ phận tuyển dụng = recruitment department

Compared with some related words:

• tuyển = recruit/select
• tuyển dụng = recruit/hire for employment
• thuê = hire/rent, often broader and not specifically an HR term

So tuyển dụng sounds especially appropriate in a professional or company context.

Thương lượng means to negotiate, to discuss terms, or sometimes to bargain depending on context.

It can be used in:

• business negotiations
• salary discussions
• contract discussions
• price bargaining

Examples:

• thương lượng giá cả = negotiate the price
• thương lượng hợp đồng = negotiate a contract

A related word is đàm phán, which also means negotiate. Often:

• thương lượng can sound a bit broader and can be used in everyday or business situations
• đàm phán often sounds more formal

Because Vietnamese often leaves out objects when they are obvious from context.

So this sentence does not explicitly say:

• recruit whom
• negotiate what

But that is normal if the listener already understands the situation.

For example, in a business context:

• tuyển dụng might imply recruit employees
• thương lượng might imply negotiate contracts, salaries, or deals

If you want to make it more explicit, you could say:

• Họ không những tuyển dụng nhân viên mà còn thương lượng hợp đồng.

That means:

• They not only recruit employees but also negotiate contracts.

Here, họ is the third-person plural pronoun meaning they.

It refers to people, but depending on context, it can also refer to:

• a group
• a team
• a company
• an organization

So họ does not have to mean only individual people in a narrow sense. English also does this sometimes:

• The company says they will expand next year.

Vietnamese works similarly in many contexts.

Yes, often you can, if the subject is already clear from context.

For example:

• Không những tuyển dụng mà còn thương lượng.

This can be acceptable if everyone already knows who is being talked about.

However, if the sentence appears by itself, keeping họ makes it clearer:

• Họ không những tuyển dụng mà còn thương lượng.

Vietnamese frequently drops subjects and objects when they are understood, but learners are usually safer including them until they are comfortable with context-based omission.

Mostly yes. The standard order is:

• không những + part 1 + mà còn + part 2

So:

• Họ không những tuyển dụng mà còn thương lượng.

is the normal structure.

If you rearrange it too much, it may sound unnatural or change the emphasis.

A good habit is to memorize the whole frame:

• không những ... mà còn ...

Then insert the two actions, qualities, or ideas into the two slots.

No. It can connect more than just verbs. It can also connect adjectives, noun phrases, and even whole clauses.

Examples:

With verbs:

• Họ không những tuyển dụng mà còn thương lượng.
• They not only recruit but also negotiate.

With adjectives:

• Cô ấy không những thông minh mà còn chăm chỉ.
• She is not only intelligent but also hardworking.

With noun phrases:

• Anh ấy không những là giáo viên mà còn là nhà văn.
• He is not only a teacher but also a writer.

So the pattern is very flexible.

It is natural, but it is slightly general.

A native speaker would understand it, especially if the context is already clear. But in real life, people often specify more detail, such as:

• Họ không những tuyển dụng nhân sự mà còn thương lượng lương.
• They not only recruit staff but also negotiate salaries.

So the original sentence is grammatically fine and natural enough, but it sounds somewhat broad because both verbs appear without objects.

That is not wrong; it just depends on how much detail the speaker wants to give.