Learn Hardcore Chinese: rúguǒ xiàyǔ, wǒmen jiù bú qù le, zěnmebàn? - If it rains, then we won’t go; what should we do?

With 就: 如果下雨，我们就不去了 feels tighter and more “so then we won’t go.”
Without 就: 如果下雨，我们不去 is still correct, just a bit flatter, less emphatic. So, 就 is not strictly required, but it’s very common and sounds natural in this pattern: 如果…就….

Why is 不 (bù) pronounced bú here?

Tone sandhi: 不 (bù) changes to bú before a fourth‑tone syllable. 去 (qù) is fourth tone, so you get bú qù.

Examples: bú shì, bú yào (before 4th tone); but bù gāo, bù máng, bù hǎo (before 1st/2nd/3rd tones) keep bù.

What does 了 (le) do in 不去了?

This 了 is sentence‑final (change‑of‑state) 了, not the perfective -了 after a verb. 不去了 means “(we’ve decided) not going anymore” or “won’t go after all.” It signals a new situation or a change of plan. You cannot have perfective -了 with 不 anyway, so the 了 here must be the sentence‑final type.

Can I just say 我们不去 or 我们就不去 without 了?

Yes. 不去 is a neutral statement about not going (habitual/future decision). 不去了 adds the nuance of “no longer going / decided not to go now.” In a conditional, both are fine; choose 了 if you want to stress the changed decision.

Why doesn’t 下雨 have a subject like “it”?

Chinese weather verbs are typically impersonal. 下雨 literally means “to fall rain,” and no subject is needed. You don’t say “它下雨”; you simply say 下雨了 (“it’s raining / it started raining”).

Why is there no 吗 at the end? Could I say 怎么办吗？

Questions with a question word (e.g., 怎么, 谁, 哪儿) do not take 吗. 怎么办？ already forms a question. 怎么办吗？ is ungrammatical.

What exactly does 怎么办 (zěnme bàn) mean? How is it different from 怎么样, 怎么做, or 做什么?

怎么办: “What should we do?/What now?” (seeking a solution or next step).
怎么样: “How about (it)/How is it?” (asking for an opinion or evaluation).
怎么做: “How to do (it)?” (asking for method/procedure).
做什么: “Do what?/What to do?” (asking for the specific action). In your sentence, 怎么办 is the natural “what should we do (then)?”

Where does 就 go? Could I say 如果下雨，就我们不去?

Place 就 in the adverb slot before the verb phrase of the result clause, usually after the subject:

Natural: 如果下雨，我们就不去了。
Not natural: 如果下雨，就我们不去。 You can also put other adverbs around it, but 就 should modify the predicate, not the subject.

Can I replace 如果 with 要是 or add 的话?

Yes:

要是下雨，我们就不去了。 (more colloquial)
下雨的话，我们就不去了。 (adds a soft conditional “in the case that”) You can also combine: 如果下雨的话，我们就不去了。

Can the condition come after the main clause?

Yes, with a pause and usually 的话:

我们就不去了，如果下雨的话。 Using 如果 clause after the main clause without 的话 sounds awkward.

What’s the difference among 不去, 不去了, 不会去, and 去不了?

不去: won’t go (decision/refusal).
不去了: not going anymore / have decided to cancel.
不会去: will not go (prediction or firm statement about the future, sometimes more objective).
去不了: cannot go (unable to, due to obstacles; ability/feasibility). Pick based on whether it’s decision, change of decision, prediction, or inability.

If I want to phrase it as a suggestion (“then let’s not go”), how can I say that?

Add 吧 or use 别:

如果下雨，我们就不去吧。 (Let’s not go then.)
如果下雨，我们就别去了。 (Then we’d better not go.)

Why use 去 and not 走?

去 means “to go (to a place).” 走 mainly means “to leave” or “to walk.” Here you’re talking about going to the planned place, so 去 is correct. 不走了 would mean “not leaving anymore,” which is different.

Is 会 natural here? Can I say 如果会下雨，我们就不去 or 我们就不会去?

如果下雨 is the most natural conditional. 如果会下雨 is possible but less common; if you want to stress likelihood, people often say 如果要下雨/如果可能下雨.
In the result clause, 我们就不会去 is fine and emphasizes a future prediction: “then we won’t (be going).”

How should I pronounce 怎么办 and 了 here?

怎么办: zěnme bàn (the 么 me is neutral tone; 办 is 4th tone).
了 in 不去了: neutral tone le. It’s the sentence‑final/change‑of‑state 了, not liǎo. Don’t confuse 不去了 (bù qù le) with 去不了 (qù bù liǎo), which uses a different liǎo meaning “cannot.”

Does the comma matter? How do I pause?

Yes. Read a natural pause after the condition:

如果下雨， (short pause) 我们就不去了， (short pause) 怎么办？ Those commas mirror how Mandarin speakers segment the thought: condition → result → follow‑up question.