Learn Hardcore Chinese: tā hé tā dōu xǐhuan kàn shū.

都 means “all/both.” It’s an adverb that comes after the subject and before the verb phrase. Pattern: A 和 B 都 + [verb phrase]. So 他和她都喜欢看书 = both of them like reading. You can also say 他们都喜欢看书.

Is 都 only for exactly two people, like English “both”?

No. 都 means “all” and works for any plural set (two or more). With two, it corresponds to “both”; with more than two, it means “all.”

Do I have to use 都? Could I just say 他和她喜欢看书?

You can. Without 都, a combined subject like 他和她 is normally understood to share the same predicate. However, 都 is very common because it makes the “both/all” meaning explicit and natural. Note that 也 (“also”) is different: 他和她也喜欢看书 adds “also,” not “both.”

Can I use 跟 (gēn) instead of 和 (hé)?

Yes. 跟 is common in speech: 他跟她都喜欢看书. 和 is a bit more formal. Both connect nouns/pronouns. To connect clauses or describe “and then,” use other words like 而且/并且/然后, not 和/跟.

In speech, how do I tell 他 and 她 apart when both are pronounced tā?

You can’t; they’re homophones. Context tells you the gender. In writing: 他 (he), 她 (she), 它 (it). For mixed-gender “they,” use 他们; for an all-female group, 她们.

What’s the correct pronunciation of 喜欢?

Standard is xǐhuan with a neutral tone on the second syllable (huan). You may hear xǐhuān, but the neutral tone is preferred in standard Mandarin.

What’s the difference between 看书 and 读书, and between 看 and 读?

看书 = “to read books” (general, everyday phrasing).
读书 can mean “to read (books)” but also “to study/attend school” depending on context.
看 often covers “look/watch/read” (e.g., 看书, 看电视), while 读 is more formal for reading text (读报纸, 读文章).
So your sentence uses the very common, natural 看书.

Why is there no “to” before “read”? How does the verb after 喜欢 work?

Chinese doesn’t use an infinitive marker like “to.” The pattern is simply 喜欢 + Verb (+ Object):

喜欢看书 (like to read/like reading)
喜欢看电影 (like to watch movies)
喜欢吃米饭 (like to eat rice)

Where do time, frequency, or place expressions go with 都?

Typical orders:

Subject + Time/Frequency + 都
- Verb (+ Object)
  - 他和她每天都看书。 (They both read every day.)
Subject + 都
- 在 + Place + Verb (+ Object)
  - 他们都在图书馆看书。 (They both read at the library.) Time words (e.g., 每天, 经常) usually come before 都; 在 + place usually comes after 都.

How do I negate this with 都? What’s the difference between 都不 and 不都?

他和她都不喜欢看书。 = Neither of them likes reading (none of them do).
他和她不都喜欢看书。 = It’s not the case that both like reading (i.e., at least one doesn’t).
Use 都不/都没 for “none of them,” and 不都 for “not all.” With 喜欢, use 不喜欢 (not 没喜欢).

If I want to specify a particular book, what changes?

Add a demonstrative and the measure word 本:

他和她都喜欢那本书/这本书。 (They both like that/this book.)
Counting a book: 一本书 (pronounced yìběn shū due to tone sandhi on 一).

Can I replace 他和她 with a shorter “both of them”?

Yes:

他们俩都喜欢看书。 (俩 liǎ = two people, colloquial)
他们两个都喜欢看书。 Both mean “the two of them both like reading.”

Could I say 他们喜欢书 instead of 喜欢看书?

他们喜欢书 means “They like books (as things/in general),” which is grammatical but less specific about the activity. 他们喜欢看书/他们爱读书 clearly means “They like reading.”

Can 和 join verbs or adjectives the way English “and” does?

Primarily, 和/跟 link nouns/pronouns. To link adjectives, use 又…又… (e.g., 他又聪明又爱看书). To link clauses/verb phrases, use 而且/并且/还/然后 as appropriate.

Is it okay to say 他们很喜欢看书? When do we add 很 or use 爱?

很喜欢 = “really/quite like,” adding intensity: 他们很喜欢看书.
爱 is stronger than 喜欢: 他们都爱看书 ≈ they love reading.
Use 很/非常/特别 etc. for degree; 都 still goes before the verb phrase.

Can I drop 书 and just say 喜欢看?

Usually no; 看 needs an object (what are you watching/reading?). You can drop it only if context already makes the object clear (e.g., A: 你在看什么？ B: 我在看。).

Why can’t 都 go between 他 and 她 (e.g., 他都和她喜欢看书)?

Because 都 modifies the predicate and takes scope over the entire subject set. It must follow the full subject phrase: 他和她都喜欢看书, not 他都和她….

Do native texts put spaces between Chinese characters like this?

No. Standard Chinese writing has no spaces between characters (except around Latin text, numbers, etc.). Spaces here are for teaching/clarity.