Learn Hardcore Chinese: rúguǒ nǐ bǎ dēng guān le, wǒ jiù bù kàn shū.

把 introduces the affected object before the verb and highlights the disposal/result of the action. Pattern: Subject + 把 + object + verb + result/complement. Here, 你把灯关了 frames “the light” as something you handle and end up turning off (completed by 了).

Do I have to use 把? Could I just say 如果你关了灯?

You don’t have to use 把. These are all natural:

如果你关了灯，我就不看书。
如果你把灯关了，我就不看书。 With 把 the effect on the object is emphasized a bit more, but both are fine.

Why is there 了 after 关? Is it past tense?

No tense is expressed. That 了 marks completion (perfective aspect): “the switching off is done.” In a conditional, it means “once (you’ve) turned off.”

Can I drop that 了 and just say 关?

You can, but it sounds less like a concrete, completed trigger. 关了 makes the conditional feel like “once you actually switch it off.” Without 了, it can sound more general or instruction-like.

Can I put a 了 at the end of the sentence too?

Yes. 如果你把灯关了，我就不看书了。 The sentence‑final 了 signals a change of state: “then I’ll stop reading (from that point).” It’s natural if you mean you will cease reading once the light goes off.

What’s the difference between the 了 after 关 and a sentence‑final 了?

Verb + 了 = completion of that verb (here, the light gets turned off).
Sentence‑final 了 = a new situation/change of state for the whole sentence (e.g., “I won’t read anymore then.”) You can have either, both, or neither, depending on the nuance.

Why is it 不 and not 没 before 看书?

不 negates a general, habitual, or future action/intention (“won’t read”). 没 negates a completed action/event (“didn’t read”). In this conditional, you’re stating an intention/result, so 不 is correct.

How would I say “can’t read” (because it’s dark) instead of “won’t read”?

不能看书 = cannot read (ability/permission).
看不了书 = can’t manage to read (due to conditions). For darkness, 看不了书 is especially natural.

Does 不 change to a rising tone bú here?

Yes. Tone sandhi: 不 (bù) becomes bú before a fourth‑tone syllable. 看 (kàn) is fourth tone, so say bú kàn.

What does 就 add? Is it required?

就 signals an immediate/natural consequence (“then/so”). It often pairs with 如果. It’s optional; dropping it is still grammatical but less tightly linked: 如果你把灯关了，我不看书.

Can I omit 如果 or 就, or both?

Yes:

Omit 就: 如果你把灯关了，我不看书。
Omit 如果: 你把灯关了，我就不看书。
Omit both (context supplies the conditional): 你把灯关了，我不看书。

Could I use 要是 or …的话 instead of 如果? Any difference?

Yes. 要是 is more colloquial; …的话 attaches to the end of the if‑clause:

要是你把灯关了，我就不看书。
你把灯关了的话，我就不看书。 如果 is neutral/slightly formal. Meaning is the same.

Why is it 看书 and not 读书? Are they the same?

看书 = read (a book). 读书 can mean “read books,” but often means “study/attend school.” Here 看书 is the default for “read.” 读书 is possible but may be heard as “study.”

Why no plural marker on 灯? How do I say “the lights”?

Chinese usually doesn’t mark plural. 灯 can mean “light(s).” To stress plurality, use:

把灯都关了 (turn all the lights off),
or add a measure: 把那两盏灯关了 / 把所有的灯关了.

Which verb is best: 关, 关掉, 关上, 关闭?

关: the default “turn off/close.” Most common with lights.
关掉: also common; often feels a bit more emphatic/completely off.
关上: more “shut/close” (doors/windows); with lights it’s less common regionally.
关闭: formal (e.g., 关闭电源). Here, 关 or 关掉 are most natural.

Can I flip the clause order: 我就不看书，如果你把灯关了?

Putting the if‑clause first is most natural. If you place it second, add …的话 to smooth it: 我就不看书，你把灯关了的话。 The standard is still: 如果你把灯关了，我就不看书。

Could I drop 你 or 我 if context is clear?

Yes. Subject omission is common:

如果把灯关了，我就不看书。
你把灯关了，我就不看。

Is the comma necessary?

Yes, in writing you normally separate the conditional and the result with a comma in 如果…，就… structures.

Is there a more compact “once… then…” version?

Yes, 一…就…:

你一关灯，我就不看书。 This pattern doesn’t usually take 把; keep the object after the verb (关灯), not 把灯关….

Any nuance difference between 关了灯 and 把灯关了?

Both are fine: 你关了灯 (S–V–O with perfective) vs 你把灯关了 (把‑construction highlighting the effect on the object). 把 tends to feel a bit more result‑focused; 关了灯 is more neutral.