Learn Hardcore Chinese: zhōumò wǒ bù xiǎng liú zài chénglǐ, zhǐ xiǎng huí lǎojiā kànkan yéye nǎinai. - On weekends I don’t want to stay in the city; I just want to go back to my hometown to visit my grandparents.

So 周末我不想留在城里 “On weekends / This weekend, I don’t want to stay in the city” is very natural.
You could also say 我周末不想留在城里, which is also correct. Putting 周末 first makes it a topic: “As for the weekend, I don’t want to stay in town; I just want to go back home…”. This kind of “topic–comment” structure is very common in Chinese.

What exactly does 留在 mean here? How is it different from just 在 or other verbs like 待?

留在 + place literally means “remain / stay at (a place)” and often implies not going elsewhere:

留在城里 – stay/remain in town (instead of going away)
留在学校 – stay at school (e.g., during a holiday)

Just 在 by itself is only the location marker “at/in”; it needs another verb:

在城里 = “in town” (no information about doing what)

Another common verb for “stay” is 待 (dāi):

待在城里 – stay in town (more colloquial)

Here 留在城里 emphasizes “remaining in the city” rather than going back home.

What’s the difference between 城里 and words like 城市 or just 城?

城里 = “in town / in the city (area)”
- Very colloquial and concrete, often contrasting city vs. countryside:
  - 我不想留在城里。 – I don’t want to stay in town.
城市 = “city” as a general, more formal noun (opposite of 乡村 “countryside”):
- 大城市 – big city
  You usually don’t say 留在城市 in this kind of personal, casual sentence.
城 by itself is an older / literary-sounding word for “city, town, walled city” and is rarely used alone in everyday modern speech.

So 城里 here feels like natural spoken Chinese: “in town / in the city (where I currently live or work).”

How does 只想 work? Why is 只 put before 想 and not somewhere else?

只 (zhǐ) is an adverb meaning “only / just”, and it normally goes before the verb phrase it limits.
Here, 想 is the main verb “to want (to do something)”, so 只想 = “only want to / just want to”:

我只想回老家。 – I only want to go back to my hometown.
我只吃素。 – I only eat vegetarian food.

You generally can’t move 只 behind 想, e.g. ✗ 想只回老家 is unnatural. What’s being limited is the wanting (I have only this desire), not the going back itself.

Why is there no 我 before 只想 in the second clause? In English we repeat “I”.

In Chinese, if two clauses share the same subject, the subject is often dropped in the second clause:

今天我很忙，也没时间休息。
(literally: Today I am very busy, also not-have time to rest.)

In your sentence, the subject of both clauses is 我, so the second 我 is simply omitted:

周末我不想留在城里，只想回老家看看爷爷奶奶。
= 周末我不想留在城里，(我)只想回老家看看爷爷奶奶。

You can say 我只想…, but leaving it out sounds more natural and less repetitive.

Why use 回 in 回老家 instead of 去老家? Aren’t both “go”?

Both 回 and 去 involve going, but:

去 = go (to some place), neutral direction:
- 去北京 – go to Beijing
回 = return / go back (to an original or previous place):
- 回家 – go back home
- 回老家 – return to one’s hometown

Because 老家 is your “home base” or place of origin, 回 is more natural than 去. Saying 回老家 already implies “go back to”, so you don’t need another verb like 去 or 来 after it.

What does 老家 really mean? Is it literally “old home”?

Literally the characters are “old + home”, but 老家 is a set phrase meaning:

hometown / home village
the place where you (or your family) are originally from, often in the countryside or a smaller town

Examples:

我老家在山东。 – My hometown is in Shandong.
过年你回老家吗？ – Are you going back to your hometown for New Year?

It doesn’t mean the physical building is old; it’s about origin and family roots, and sometimes where your grandparents or extended family still live.

Why is it 看看爷爷奶奶 and not just 看爷爷奶奶? What does the repetition 看看 do?

Reduplicating a one-syllable verb (看 → 看看) is very common in Mandarin. It usually makes the action sound:

lighter / shorter in duration
more casual or friendly
less “heavy” or demanding

So:

看爷爷奶奶 – see/visit grandparents (neutral)
看看爷爷奶奶 – go (and) see the grandparents a bit, pay them a short visit, check on them

Other examples:

想想 – think a bit
试试 – give it a try
问问 – (just) ask

In English this often feels like “have a look / drop by / go see them” rather than a formal “visit”.

Do 爷爷 and 奶奶 mean all grandparents, or only certain ones?

In standard Mandarin family terms:

爷爷 – paternal grandfather (father’s father)
奶奶 – paternal grandmother (father’s mother)

Maternal grandparents are usually:

外公 / 姥爷 – maternal grandfather
外婆 / 姥姥 – maternal grandmother

In everyday speech, though, 爷爷 and 奶奶 are also commonly used to politely address elderly men and women (like saying “Grandpa / Grandma” to strangers), but in a family context they usually refer to your grandparents on your father’s side.

Why is 不 pronounced bù here and not bú? I learned that 不 sometimes changes tone.

You’re right: 不 (bù) changes tone in certain contexts:

Normally: bù (4th tone)
Before another 4th‑tone syllable, it usually changes to bú (2nd tone):
- 不对 → bú duì
- 不要 → bú yào

In your sentence, 不想 is bù xiǎng because 想 (xiǎng) is 3rd tone, not 4th.
So there’s no sandhi change here, and it stays as bù.

What’s the nuance of 想 in 不想留在城里，只想回老家…? How is it different from 要 or 想要?

Here 想 + verb means “want to / feel like (doing something)” and often sounds softer or more about desire than about firm intention:

我想回老家。 – I’d like to go back to my hometown.
我不想留在城里。 – I don’t feel like staying in town.

Compare:

要 + verb – “to be going to / must / really intend to”
- 我周末要回老家。 – I’m going to / I will go back this weekend. (stronger)
想要 + noun – often “want to have (something)”
- 我想要一辆车。 – I want a car.

So in this sentence, 想 expresses the speaker’s wish or preference, not a hard plan.

Why isn’t there any tense marker like “will” or 了 in this sentence? How do we know it’s about a future weekend?

Chinese doesn’t change the verb form for past/present/future the way English does. Time is usually indicated by time words (like 周末, 明天, 昨天) and by context.

周末我不想留在城里。
Could mean “On weekends (in general) I don’t want to stay in town” or “This weekend I don’t want to stay in town,” depending on context.

The particle 了 is mainly for completed actions or a change of state, not for “future tense”. Since the sentence is expressing a current desire about the weekend, not a completed action, no 了 is needed. If you wanted to be very explicit about the time, you could say 这个周末 (“this weekend”).