tā xué zhōngwén bú shì wèile kǎoshì, érshì yīnwèi duì zhōngwén yǒu xìngqù.

It means not ..., but rather ....

In this sentence:

• 他学中文不是为了考试 = He studies Chinese not for exams
• 而是因为对中文有兴趣 = but rather because he is interested in Chinese

So 不是……而是…… is used to correct or replace one idea with another:

• 不是 A，而是 B
• It’s not A, but B

This is a very common pattern in Chinese.

This is because of tone sandhi.

Normally, 不 is fourth tone: bù.
But when 不 comes before another fourth-tone syllable, it changes to second tone: bú.

Here:

• 是 shì is fourth tone
• so 不 + 是 becomes bú shì

This only changes the pronunciation, not the meaning.

They mean different things:

• 为了 = for the sake of, in order to → expresses purpose
• 因为 = because → expresses reason

So:

• 为了考试 = for the purpose of taking/passing exams
• 因为对中文有兴趣 = because he is interested in Chinese

The sentence contrasts purpose and real reason:

• He is not studying Chinese in order to pass exams
• He is studying Chinese because he likes it

Because the sentence is making a contrast between purpose and motivation.

• 为了考试 = studying Chinese for exams, as a goal
• 因为对中文有兴趣 = studying Chinese because of interest, as the reason

If you said 不是因为考试, that would mean not because of exams, which sounds a little different. It focuses on cause, not purpose.

So 为了考试 is the natural choice if you want to say he is not learning Chinese as an exam-driven activity.

Literally, it means:

• 对 = toward / regarding
• 中文 = Chinese language
• 有 = have
• 兴趣 = interest

So:

• 对中文有兴趣 = to have interest in Chinese

A natural English translation is:

• to be interested in Chinese

Chinese often uses 有 + noun where English uses an adjective:

• 有兴趣 = have interest = be interested

Yes, it is a very common pattern.

The structure is:

• 对 + something + 有兴趣
• to be interested in something

Examples:

• 我对历史有兴趣。
  I’m interested in history.
• 他对音乐有兴趣。
  He’s interested in music.

A very common alternative is:

• 对……感兴趣

So:

• 对中文有兴趣
• 对中文感兴趣

Both mean to be interested in Chinese.
感兴趣 is often a little more common in everyday speech, but 有兴趣 is perfectly natural.

Because 因为 introduces the reason.

The structure is:

• 因为 + reason

Here, the reason is:

• 对中文有兴趣

So:

• 因为对中文有兴趣
• because he is interested in Chinese

Chinese often puts the reason directly after 因为 without adding extra words.

Because the subject is understood from the first clause.

The full idea would be:

• 他学中文不是为了考试，而是他因为对中文有兴趣。

But that version sounds awkward and unnecessary. In Chinese, when the subject stays the same, it is often omitted in the second clause.

So the natural sentence is:

• 他学中文不是为了考试，而是因为对中文有兴趣。

English does this too sometimes, but Chinese does it even more often.

Yes. That is also natural.

Compare:

• 他学中文不是为了考试，而是因为对中文有兴趣。
• 他不是为了考试学中文，而是因为对中文有兴趣。

Both mean basically the same thing.

The difference is mainly focus:

• 他学中文不是为了考试 emphasizes his studying Chinese
• 他不是为了考试学中文 emphasizes not for exams

Both are grammatical and common.

In this sentence, 中文 means the Chinese language in a general sense.

Depending on context, 中文 can refer to:

• Chinese language overall
• Chinese as a school subject
• written Chinese more specifically

But in 学中文, it usually means learn/study Chinese in general.

So here it most naturally means:

• He studies/learns Chinese

Both are possible.

• 学中文 = learn/study Chinese
• 学习中文 = study/learn Chinese

The difference is mostly style:

• 学 is shorter and very common in everyday speech
• 学习 is a bit more formal

So:

• 他学中文 sounds natural and conversational
• 他学习中文 is also correct, but slightly more formal or textbook-like

考试 usually means exam or test.

It can refer to:

• taking an exam
• an exam as an event
• exams in general

In this sentence, 为了考试 most naturally means:

• for exams
• for the sake of passing exams
• because of exam needs

Chinese often leaves this kind of phrase general, without needing an or the like English does.

Because Chinese does not use articles like English does.

English needs words like:

• a
• an
• the

Chinese usually does not.

So:

• 学中文 = study Chinese
• 为了考试 = for exams / for the exam context
• 对中文有兴趣 = be interested in Chinese

The exact English article depends on context, but Chinese does not need one.

No, 而是 and 但是 are not the same here.

• 但是 means but/however
• 而是 is specifically used in the pattern 不是……而是……

So in this sentence, 而是 is the correct choice because it completes the contrast:

• 不是为了考试，而是因为对中文有兴趣

If you used 但是, it would sound unnatural here because the sentence is not just adding a contrast; it is replacing one explanation with another.

It talks about both.

• 为了考试 = a possible goal/purpose
• 因为对中文有兴趣 = the actual reason/motivation

So the sentence says:

• His study of Chinese is not goal-driven by exams
• It is motivated by genuine interest

This is why the sentence feels stronger than a simple He likes Chinese. It specifically contrasts external pressure with personal interest.