Learn Hardcore Chinese: tā hái xiǎng mǎi nà běn shū.

As “still” (continuation of a previous state): 她之前就想买那本书，现在还想买。= She already wanted it before; she still wants it now.
As “also/in addition” (adding another item or action by the same subject): 她想买这本书，还想买那本书。= She wants to buy this book and also that one.

Where should bold 还 go in the sentence?

Place 还 right after the subject and before the main verb or adjective.

Correct: 她还想买那本书。
Don’t say: 她想还买那本书 (unnatural for this meaning).
Note: If you’re stating an additional completed action, you can say 她还买了那本书 (She also bought that book).

What’s the nuance difference between bold 想, 要, and 想要?

想 + V: would like to; a tentative or polite desire. 她想买那本书。
要 + V: intend to/will; stronger determination or plan. 她要买那本书。
想要 + N/V: want (to have); with nouns it’s common: 她想要那本书。 With verbs, it’s common in Taiwan; on the Mainland, many prefer 想 + V or 要 + V.

Why is bold 本 between bold 那 and bold 书? Can I say 那书?

Chinese requires a measure word (classifier) with demonstratives and numbers. For books, the classifier is 本:

Pattern: 这/那 + 量词 + 名词 → 那本书
Saying 那书 is unnatural in standard Mandarin.

Can I use bold 个 instead of bold 本 and say 那个书?

No. 书 has a specific classifier 本, so 那个书 sounds wrong. Use 那本书. The general classifier 个 is for nouns without a specific classifier or in some casual contexts, but not for 书.

Is bold 还 pronounced hái or huán here?

Here it’s hái (“still; also”). The pronunciation huán belongs to a different word meaning “to return” (e.g., 还书 huán shū = return a book).

How do tones change when saying the whole sentence naturally?

Underlying pinyin with tones: tā hái xiǎng mǎi nà běn shū
Third-tone sandhi: xiǎng mǎi → xiáng mǎi
Colloquial option: 那 nà often becomes nèi before a classifier: nèi běn
A natural read: tā hái xiáng mǎi nèi běn shū

I mix up bold 那 (nà/nèi) “that” and bold 哪 (nǎ) “which.” How do I tell them apart?

那 (nà/nèi) = that. Example: 那本书 (that book).
哪 (nǎ) = which. Example: 哪本书 (which book?). They differ in tone and meaning: nà/nèi is 4th tone; nǎ is 3rd tone.

Can I drop bold 买 and say 她还想那本书?

No. You need a main verb. 想 alone means “to think” or “to miss,” not “want (that thing)” unless you use 想要:

Want that book: 她想要那本书 / 她要那本书。
Want to buy that book: 她想买那本书 / 她要买那本书。

Why is there no bold 了 here? How would I say “She still hasn’t bought that book”?

The sentence expresses desire, not a completed action, so no 了. To say “still hasn’t bought”:

她还没(有)买那本书。 = She still hasn’t bought that book. To emphasize the ongoing state, you can add a particle:
她还想买那本书呢。 (soft, “still” feel)

How do I say “buy it again” or “buy another copy”?

Future repetition: use 再. 她想再买那本书。= She wants to buy that book again.
Past repetition: use 又 (+ 了). 她又买了那本书。= She bought that book again.
Another copy: 她想再买一本。(Context implies the same book.)

Can I omit bold 那 to mean books in general?

Yes.

她还想买书 = She still wants to buy books (general/unspecified).
她还想买那本书 = She still wants to buy that specific book.

How do I emphasize “that exact book”?

Add the numeral for focus: 那一本书 (that very one).
Or use focus: 就是那本书。For example: 她还想买，就是那本书。

Can I front the object for emphasis?

Yes, topicalization is natural:

那本书，她还想买。 = As for that book, she still wants to buy it. This highlights the topic “that book.”

Any common mix-ups between bold 买 (mǎi) “buy” and bold 卖 (mài) “sell”?

Yes—tone confusion flips the meaning.

买 mǎi (3rd tone) = buy. 她还想买那本书。
卖 mài (4th tone) = sell. 她还想卖那本书。= She still wants to sell that book.

Are there other measure words for reading materials I should know?

一本杂志 (a magazine). You can also specify issue: 一期杂志 (one issue).
一份报纸 (a newspaper).
Books take 本: 一本/那本书.